Substrate treatment apparatus, and substrate treatment method

ABSTRACT

The inventive substrate treatment apparatus includes: a rotative treatment control unit which controls a first chemical liquid supplying unit and a second chemical liquid supplying unit to perform a first chemical liquid supplying step of supplying a first chemical liquid to a substrate rotated by a substrate holding and rotating mechanism and a second chemical liquid supplying step of supplying a second chemical liquid to the substrate rotated by the substrate holding and rotating mechanism after the first chemical liquid supplying step; and a cleaning control unit which controls the cleaning liquid supplying unit to spout the cleaning liquid from the cleaning liquid outlet port to supply the cleaning liquid to the cup inner wall and/or the base wall surface before start of the second chemical liquid supplying step after end of the first chemical liquid supplying step, and/or during and/or after the second chemical liquid supplying step.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.14/822,242, filed Aug. 10, 2015, which claims the benefit of JapanesePatent Application Nos. 2014-165555, filed Aug. 15, 2014 and JP2014-165556, filed Aug. 15, 2014, which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate treatment apparatus and asubstrate treatment method for treating a substrate with a chemicalliquid. Examples of the substrate to be treated include semiconductorwafers, substrates for liquid crystal display devices, substrates forplasma display devices, substrates for FED (Field Emission Display)devices, substrates for optical disks, substrates for magnetic disks,substrates for magneto-optical disks, substrates for photo masks,ceramic substrates and substrates for solar cells.

2. Description of the Related Art

In production processes for semiconductor devices and liquid crystaldisplay devices, a substrate treatment apparatus of a single substratetreatment type adapted to treat a single substrate at a time is used fortreating a front surface of a substrate such as a semiconductor wafer ora liquid crystal display panel glass substrate with a chemical liquid.The substrate treatment apparatus of the single substrate treatment typeincludes a treatment chamber defined by a partition wall, a substrateholding and rotating mechanism which generally horizontally holds thesubstrate and rotates the substrate, a bottomed cylindrical treatmentcup which accommodates the substrate holding and rotating mechanism, anda chemical liquid nozzle which supplies the chemical liquid to thesubstrate held by the substrate holding and rotating mechanism. Thesubstrate holding and rotating mechanism, the treatment cup and thechemical liquid nozzle are provided in the treatment chamber.

The treatment cup includes a fixed cup, and a guard vertically movablewith respect to the cup and capable of receiving a chemical liquidscattered from the substrate rotated by the substrate holding androtating mechanism. A treatment liquid received by the guard flows on aninner wall of the guard into the cup.

In the substrate treatment apparatus, plural types of chemical liquidsare often used. Where chemical liquids which are liable to cause ahazard when being accidentally brought into contact with each other ormixed together, e.g., a sulfuric acid-containing liquid such as asulfuric acid/hydrogen peroxide mixture (SPM) and an organic solventsuch as isopropyl alcohol (IPA), are used in combination (i.e., thechemical liquids to be used in combination are inappropriate for mixingthereof), the accidental mixing of the chemical liquids should bereliably prevented. In general, therefore, different treatment chambersare used for treatment with different types of chemical liquids asdisclosed in JP2007-103732A. Where an inappropriate combination ofchemical liquids are used for the treatment in a single treatmentchamber, a so-called interlock process is employed for preventing theaccidental mixing of the chemical liquids in the treatment chamber. Inthe interlock process, when one of the chemical liquids is supplied, theopening of a chemical liquid valve for the other chemical liquid isprohibited or, when a detected rotation speed of the substrate fallsoutside a predetermined rotation speed range, the opening of chemicalliquid valves for the chemical liquids is prohibited (see, for example,JP4917469 and JP4917470).

SUMMARY OF THE INVENTION

Even if plural types of chemical liquids to be used in combination forthe substrate treatment are inappropriate for mixing thereof, it issometimes desirable to complete the substrate treatment in the singletreatment chamber for improvement of the productivity. To meet thedesired demand, the accidental mixing of the chemical liquids should bereliably prevented not only in the treatment chamber but also in thesubstrate holding and/or rotating mechanism and the cup.

Further, a vat for receiving the chemical liquid is provided on theentire bottom of the treatment chamber so that a chemical liquiddripping or leaking from the chemical liquid nozzle can be preventedfrom flowing out of the treatment chamber. The vat has a drain port, anda drainpipe is connected to the drain port. The chemical liquid receivedin the vat is guided toward the drain port on an upper surface of thevat to be drained outside the apparatus from the drain port through thedrain pipe. Where the treatment is performed with the use of theinappropriate combination of the chemical liquids in the singletreatment chamber and the chemical liquids are received in the same vat,there is a possibility that the accidental mixing of the chemicalliquids occurs on the upper surface of the vat.

It is therefore an object of the present invention to provide asubstrate treatment apparatus and a substrate treatment method which,even if plural types of chemical liquids to be used in combination forsubstrate treatment are inappropriate for mixing thereof, reliablyprevent the accidental mixing of the chemical liquids and complete thesubstrate treatment in a single treatment chamber.

It is another object of the present invention to provide a substratetreatment apparatus which reliably prevents the accidental mixing of theinappropriate combination of the chemical liquids on the vat.

According to a first inventive aspect, there is provided a substratetreatment apparatus which includes: a treatment chamber; a substrateholding and rotating mechanism provided in the treatment chamber andincluding a spin base rotatable about a predetermined rotation axis forholding the substrate and rotating the substrate about the rotationaxis; an annular cup provided around the substrate holding and rotatingmechanism for retaining a treatment liquid expelled from the substraterotated by the substrate holding and rotating mechanism; a firstchemical liquid supplying unit which supplies a first chemical liquid tothe substrate held by the substrate holding and rotating mechanism; asecond chemical liquid supplying unit which supplies a second chemicalliquid different from the first chemical liquid to the substrate held bythe substrate holding and rotating mechanism; a cleaning liquid nozzlehaving a cleaning liquid outlet port for spouting a cleaning liquidtoward a cup inner wall which is an inner wall of the cup and/or a basewall surface which is a wall surface of an outer periphery of the spinbase; a cleaning liquid supplying unit which supplies the cleaningliquid to the cleaning liquid nozzle; a rotative treatment control unitwhich controls the first chemical liquid supplying unit and the secondchemical liquid supplying unit to perform a first chemical liquidsupplying step of supplying the first chemical liquid to the substraterotated by the substrate holding and rotating mechanism and a secondchemical liquid supplying step of supplying the second chemical liquiddifferent from the first chemical liquid to the substrate rotated by thesubstrate holding and rotating mechanism after the first chemical liquidsupplying step; and a cleaning control unit which controls the cleaningliquid supplying unit to spout the cleaning liquid from the cleaningliquid outlet port to supply the cleaning liquid to the cup inner walland/or the base wall surface before the start of the second chemicalliquid supplying step after the end of the first chemical liquidsupplying step, and/or during and/or after the second chemical liquidsupplying step.

With this arrangement, the first chemical liquid supplying step and thesecond chemical liquid supplying step are performed in this order in thesame treatment chamber. Further, the cleaning liquid is supplied to thecup inner wall and/or the base wall surface before the start of thesecond chemical liquid supplying step after the end of the firstchemical liquid supplying step, and/or during and/or after the secondchemical liquid supplying step.

Where the cleaning liquid is supplied to the cup inner wall and/or thebase wall surface before the start of the second chemical liquidsupplying step after the end of the first chemical liquid supplyingstep, the first chemical liquid can be removed from the cup inner walland/or the base wall surface by the supply of the cleaning liquid. Atthe start of the second chemical liquid supplying step, therefore, thefirst chemical liquid remains neither on the cup inner wall nor on thebase wall surface. This reliably prevents the first chemical liquid andthe second chemical liquid from being accidentally brought into contactwith each other or mixed together in the second chemical liquidsupplying step.

Where the cleaning liquid is supplied to the cup inner wall and/or thebase wall surface in the second chemical liquid supplying step and/orafter the second chemical liquid supplying step, the second chemicalliquid can be removed from the cup inner wall and/or the base wallsurface by the supply of the cleaning liquid. At the start of the firstchemical liquid supplying step for the next substrate treatment,therefore, the second chemical liquid remains neither on the cup innerwall nor on the base wall surface. This reliably prevents the firstchemical liquid and the second chemical liquid from being accidentallybrought into contact with each other or mixed together in the firstchemical liquid supplying step.

Thus, even if the plural types of chemical liquids (the first chemicalliquid and the second chemical liquid) to be used in combination for thesubstrate treatment are inappropriate for mixing thereof, the substratetreatment apparatus can reliably prevent the accidental mixing of thechemical liquids and complete the substrate treatment in the singletreatment chamber.

The expression “the chemical liquids to be used in combination areinappropriate for mixing thereof” herein means not only “a combinationof chemical liquids which are liable to cause a hazard when beingaccidentally mixed together” but also “a combination of chemical liquidswhich are liable to produce a reaction product when being accidentallymixed together” and “a combination of chemical liquids which are liableto have difficulty in separation and recovery when being accidentallymixed together.” An exemplary combination of the chemical liquids whichare liable to produce a reaction product when being accidentally mixedtogether is a combination of an acid and an alkali, which produce a saltto contaminate the inside of the apparatus. An exemplary combination ofchemical liquids which are liable to have difficulty in separation andrecovery when being accidentally mixed together is a combination of HF(hydrofluoric acid) and SPM (sulfuric acid/hydrogen peroxide mixture).

According to an embodiment of the present invention, the rotativetreatment control unit includes a rinsing control unit which performs arinsing step of supplying a rinse liquid to the substrate rotated by thesubstrate holding and rotating mechanism to rinse away the firstchemical liquid from the front surface of the substrate before the startof the second chemical liquid supplying step after the end of the firstchemical liquid supplying step, and the cleaning control unit includes afirst cleaning control unit which spouts the cleaning liquid from thecleaning liquid outlet port in the rinsing step and/or before the startof the second chemical liquid supplying step after the end of therinsing step.

With this arrangement, the first chemical liquid supplying step, therinsing step and the second chemical liquid supplying step are performedin this order in the same treatment chamber. Further, the cleaningliquid is supplied to the cup inner wall and/or the base wall surface inthe rinsing step after the first chemical liquid supplying step and/orbefore the start of the second chemical liquid supplying step after theend of the rinsing step.

After the end of the first chemical liquid supplying step, the firstchemical liquid is liable to adhere to (or remain on) the cup inner walland/or the base wall surface. If the second chemical liquid supplyingstep is started in this state, there is a possibility that the firstchemical liquid and the second chemical liquid are accidentally broughtinto contact with each other or mixed together in the second chemicalliquid supplying step.

With the inventive arrangement, in contrast, the cleaning liquid issupplied to the cup inner wall and/or the base wall surface in therinsing step to be performed after the first chemical liquid supplyingstep and/or before the start of the second chemical liquid supplyingstep after the rinsing step. Thus, the first chemical liquid is removedfrom the cup inner wall and/or the base wall surface before the start ofthe second chemical liquid supplying step. At the start of the secondchemical liquid supplying step, therefore, the first chemical liquidremains neither on the cup inner wall nor on the base wall surface. Thisreliably prevents the accidental mixing of the first chemical liquid andthe second chemical liquid in the second chemical liquid supplying step.

The cleaning control unit may include a second cleaning control unitwhich spouts the cleaning liquid from the cleaning liquid outlet port inthe second chemical liquid supplying step.

With this arrangement, the cleaning liquid is supplied to the cup innerwall and/or the base wall surface in the second chemical liquidsupplying step.

If the first chemical liquid supplying step for the next substratetreatment is started with the second chemical liquid adhering to (orremaining on) the cup inner wall and/or the base wall surface after theend of the second chemical liquid supplying step, there is a possibilitythat the first chemical liquid and the second chemical liquid areaccidentally brought into contact with each other or mixed together.

With the inventive arrangement, in contrast, the cleaning liquid issupplied to the cup inner wall and/or the base wall surface in thesecond chemical liquid supplying step and/or after the end of the secondchemical liquid supplying step. Thus, the second chemical liquid can beremoved from the cup inner wall and/or the base wall surface. At thestart of the next substrate treatment, therefore, the second chemicalliquid remains neither on the cup inner wall nor on the base wallsurface. This reliably prevents the accidental mixing of the firstchemical liquid and the second chemical liquid in the first chemicalliquid supplying step for the next substrate treatment.

The rotative treatment control unit may include a spin drying controlunit which performs a spin drying step of causing the substrate holdingand rotating mechanism to rotate the substrate to spin off liquid fromthe front surface of the substrate after the end of the second chemicalliquid supplying step. The cleaning control unit may include a thirdcleaning control unit which spouts the cleaning liquid from the cleaningliquid outlet port in the spin drying step.

With this arrangement, the cleaning liquid is supplied to the cup innerwall and/or the base wall surface in the spin drying step.

If the first chemical liquid supplying step for the next substratetreatment is started with the second chemical liquid adhering to (orremaining on) the cup inner wall and/or the base wall surface after theend of the spin drying step, there is a possibility that the firstchemical liquid and the second chemical liquid are accidentally broughtinto contact with each other or mixed together.

With the inventive arrangement, in contrast, the cleaning liquid issupplied to the cup inner wall and/or the base wall surface in the spindrying step. Thus, the second chemical liquid can be removed from thecup inner wall and/or the base wall surface. After the end of the spindrying step, therefore, the second chemical liquid remains neither onthe cup inner wall nor on the base wall surface. This reliably preventsthe accidental mixing of the first chemical liquid and the secondchemical liquid in the first chemical liquid supplying step for the nextsubstrate treatment.

The substrate treatment apparatus may further include: a common pipeconnected to a drain/recovery port provided in a bottom of the cup; arecovery pipe connected to the common pipe for recovering the firstchemical liquid or the second chemical liquid; a drain pipe connected tothe common pipe; a switch valve which switches a destination of liquidflowing through the common pipe between the recovery pipe and the drainpipe; and a destination setting control unit which controls the switchvalve so that the destination of the liquid flowing through the commonpipe is set to the drain pipe, while causing the cleaning control unitto supply the cleaning liquid.

With this arrangement, the destination of the liquid flowing through thecommon pipe is set to the drain pipe, while the cleaning liquid issupplied to the cup inner wall and/or the base wall surface. Therefore,the cleaning liquid supplied to the cup inner wall and/or the base wallsurface is guided to the common pipe through the drain/recovery port ofthe cup, and then to the drain pipe. Even if the first chemical liquidor the second chemical liquid adheres to a pipe wall of the common pipein the first chemical liquid supplying step or the second chemicalliquid supplying step, therefore, the first chemical liquid or thesecond chemical liquid can be washed away from the pipe wall with thecleaning liquid flowing through the common pipe. This reliably preventsthe first chemical liquid and the second chemical liquid from beingaccidentally brought into contact with each other or mixed together onthe pipe wall of the common pipe.

The cleaning liquid nozzle may include a first cleaning liquid nozzlehaving a first cleaning liquid outlet port to be opposed to the basewall surface.

The first cleaning liquid nozzle may be disposed with the first cleaningliquid outlet port directed obliquely upward. With this arrangement, thefirst cleaning liquid nozzle can be disposed obliquely below the basewall surface. If the first cleaning liquid nozzle was disposed on alateral side of the base wall surface, the first cleaning liquid nozzlewould be located between the spin base and the cup as seen in plan,resulting in size increase of the substrate treatment apparatus. In thepresent invention, in contrast, the first cleaning liquid nozzle is notlocated on the lateral side of the base wall surface, so that the sizeof the substrate treatment apparatus is not increased. Thus, thesubstrate treatment apparatus is adapted to supply the cleaning liquidto the base wall surface without size increase thereof. Since thecleaning liquid is supplied to the base wall surface obliquely frombelow, the first or second chemical liquid can be advantageously removedfrom the bottom surface of the outer periphery of the spin base.

The cleaning liquid nozzle may include a second cleaning liquid nozzlehaving a second cleaning liquid outlet port for supplying the cleaningliquid to the cup inner wall.

In this case, the cup may annularly surround the substrate holding androtating mechanism, and may have a drain port provided in a bottom wallthereof. The second cleaning liquid outlet port may include a pluralityof second cleaning liquid outlet ports provided circumferentially of thecup laterally of the spin chuck. The second cleaning liquid outlet portsmay be absent in a region near the drain port.

With this arrangement, the second cleaning liquid outlet ports areabsent in the region near the drain port, so that the cleaning liquidspouted from the second cleaning liquid outlet ports movescircumferentially toward the drain port in the cup and is guided fromthe drain port to the common pipe. That is, a distance for which thecleaning liquid moves in the cup is increased. Thus, the first or secondchemical liquid can be efficiently removed from the cup.

The first chemical liquid may be a sulfuric acid-containing liquid. Thesecond chemical liquid may be an organic solvent. Examples of thesulfuric acid-containing liquid include SPM and sulfuric acid. Examplesof the organic solvent include IPA, methanol, ethanol, HFE(hydrofluoroether) and acetone, at least one of which is used.

According to a second aspect of the present invention, there is provideda substrate treatment method for treating a substrate by using asubstrate treatment apparatus which includes: a substrate holding androtating mechanism having a spin base rotatable about a predeterminedrotation axis for holding the substrate and rotating the substrate aboutthe rotation axis; a cup provided around the substrate holding androtating mechanism for retaining a treatment liquid expelled from thesubstrate rotated by the substrate holding and rotating mechanism; and acleaning liquid nozzle which spouts a cleaning liquid toward a cup innerwall which is an inner wall of the cup and/or a base wall surface whichis a wall surface of an outer periphery of the spin base, the methodincluding: a first chemical liquid supplying step of supplying a firstchemical liquid to the substrate rotated by the substrate holding androtating mechanism; a second chemical liquid supplying step of supplyinga second chemical liquid different from the first chemical liquid to thesubstrate rotated by the substrate holding and rotating mechanism afterthe first chemical liquid supplying step; and a cleaning liquidsupplying step of spouting the cleaning liquid from the cleaning liquidnozzle to supply the cleaning liquid to the cup inner wall and/or thebase wall surface before the start of the second chemical liquidsupplying step after the end of the first chemical liquid supplyingstep, and/or during and/or after the second chemical liquid supplyingstep.

In this method, the first chemical liquid supplying step and the secondchemical liquid supplying step are performed in this order in the sametreatment chamber. The cleaning liquid is supplied to the cup inner walland/or the base wall surface before the start of the second chemicalliquid supplying step after the end of the first chemical liquidsupplying step, and/or during and/or after the second chemical liquidsupplying step.

Where the cleaning liquid is supplied to the cup inner wall and/or thebase wall surface before the start of the second chemical liquidsupplying step after the end of the first chemical liquid supplyingstep, the first chemical liquid can be removed from the cup inner walland/or the base wall surface by the supply of the cleaning liquid. Atthe start of the second chemical liquid supplying step, therefore, thefirst chemical liquid remains neither on the cup inner wall nor on thebase wall surface. This reliably prevents the first chemical liquid andthe second chemical liquid from being accidentally brought into contactwith each other or mixed together in the second chemical liquidsupplying step.

Where the cleaning liquid is supplied to the cup inner wall and/or thebase wall surface in the second chemical liquid supplying step and/orafter the second chemical liquid supplying step, the second chemicalliquid can be removed from the cup inner wall and/or the base wallsurface by the supply of the cleaning liquid. At the start of the firstchemical liquid supplying step for the next substrate treatment,therefore, the second chemical liquid remains neither on the cup innerwall nor on the base wall surface. This reliably prevents the firstchemical liquid and the second chemical liquid from being accidentallybrought into contact with each other or mixed together in the firstchemical liquid supplying step.

Thus, even if the plural types of chemical liquids (the first chemicalliquid and the second chemical liquid) to be used in combination for thesubstrate treatment are inappropriate for mixing thereof, the substratetreatment method can reliably prevent the accidental mixing of thechemical liquids and complete the substrate treatment in the singletreatment chamber.

According to an embodiment of the present invention, the substratetreatment method further includes a rinsing step of supplying a rinseliquid to the substrate rotated by the substrate holding and rotatingmechanism to rinse away the first chemical liquid from the front surfaceof the substrate before the start of the second chemical liquidsupplying step after the end of the first chemical liquid supplyingstep, and the cleaning liquid supplying step includes a first cleaningliquid supplying step of spouting the cleaning liquid from the cleaningliquid nozzle in the rinsing step and/or before the start of the secondchemical liquid supplying step after the end of the rinsing step.

In this method, the first chemical liquid supplying step, the rinsingstep and the second chemical liquid supplying step are performed in thisorder in the same treatment chamber. Further, the cleaning liquid issupplied to the cup inner wall and/or the base wall surface in therinsing step after the first chemical liquid supplying step and/orbefore the start of the second chemical liquid supplying step after theend of the rinsing step.

After the end of the first chemical liquid supplying step, the firstchemical liquid is liable to adhere to (or remain on) the cup inner walland/or the base wall surface. If the second chemical liquid supplyingstep is started in this state, there is a possibility that the firstchemical liquid and the second chemical liquid are accidentally broughtinto contact with each other or mixed together in the second chemicalliquid supplying step.

In the inventive method, in contrast, the cleaning liquid is supplied tothe cup inner wall and/or the base wall surface in the rinsing step tobe performed after the first chemical liquid supplying step and/orbefore the start of the second chemical liquid supplying step after therinsing step. Thus, the first chemical liquid is removed from the cupinner wall and/or the base wall surface before the start of the secondchemical liquid supplying step. At the start of the second chemicalliquid supplying step, therefore, the first chemical liquid remainsneither on the cup inner wall nor on the base wall surface. Thisreliably prevents the accidental mixing of the first chemical liquid andthe second chemical liquid in the second chemical liquid supplying step.

The cleaning liquid supplying step may include a second cleaning liquidsupplying step of spouting the cleaning liquid from the cleaning liquidnozzle in the second chemical liquid supplying step and/or after the endof the second chemical liquid supplying step.

In this method, the cleaning liquid is supplied to the cup inner walland/or the base wall surface in the second chemical liquid supplyingstep.

If the first chemical liquid supplying step for the next substratetreatment is started with the second chemical liquid adhering to (orremaining on) the cup inner wall and/or the base wall surface after theend of the second chemical liquid supplying step, there is a possibilitythat the first chemical liquid and the second chemical liquid areaccidentally brought into contact with each other or mixed together.

In the inventive method, in contrast, the cleaning liquid is supplied tothe cup inner wall and/or the base wall surface in the second chemicalliquid supplying step and/or after the end of the second chemical liquidsupplying step. Thus, the second chemical liquid can be removed from thecup inner wall and/or the base wall surface. At the start of the nextsubstrate treatment, therefore, the second chemical liquid remainsneither on the cup inner wall nor on the base wall surface. Thisreliably prevents the accidental mixing of the first chemical liquid andthe second chemical liquid in the first chemical liquid supplying stepfor the next substrate treatment.

The substrate treatment method may further include a spin drying step ofcausing the substrate holding and rotating mechanism to rotate thesubstrate to spin off liquid from a front surface of the substrate afterthe end of the second chemical liquid supplying step. The cleaningliquid supplying step may include a third cleaning liquid supplying stepof spouting the cleaning liquid from the cleaning liquid nozzle in thespin drying step and/or after the spin drying step.

In this method, the cleaning liquid is supplied to the cup inner walland/or the base wall surface in the spin drying step.

If the first chemical liquid supplying step for the next substratetreatment is started with the second chemical liquid adhering to (orremaining on) the cup inner wall and/or the base wall surface after theend of the spin drying step, there is a possibility that the firstchemical liquid and the second chemical liquid are accidentally broughtinto contact with each other or mixed together.

In the inventive method, in contrast, the cleaning liquid is supplied tothe cup inner wall and/or the base wall surface in the spin drying step.Thus, the second chemical liquid can be removed from the cup inner walland/or the base wall surface. After the end of the spin drying step,therefore, the second chemical liquid remains neither on the cup innerwall nor on the base wall surface. This reliably prevents the accidentalmixing of the first chemical liquid and the second chemical liquid inthe first chemical liquid supplying step for the next substratetreatment.

The cup may include a plurality of cups disposed in non-overlappingrelation as seen in plan. In this case, a first cup located at theinnermost position out of the plurality of cups may be cleaned in thecleaning liquid supplying step.

In this method, the cleaning liquid is supplied to the first cup locatedat the innermost position in the cleaning liquid supplying step. Sincethe first cup is located closest to the substrate holding and rotatingmechanism, the first or second chemical liquid is liable to flow intothe first cup to adhere to an inner wall of the first cup during thetreatment with the first chemical liquid or the second chemical liquid.However, the inner wall of the first cup to which the first or secondchemical liquid is liable to adhere can be cleaned with the cleaningliquid. This reliably prevents the accidental mixing of the firstchemical liquid and the second chemical liquid.

The substrate treatment apparatus may further include: a common pipeconnected to a drain/recovery port provided in a bottom of the cup; arecovery pipe connected to the common pipe for recovering the firstchemical liquid or the second chemical liquid; and a drainpipe connectedto the common pipe. In this case, the cleaning step may be performedwith a destination of liquid flowing through the common pipe being setto the drain pipe.

In this method, the destination of the liquid flowing through the commonpipe is set to the drain pipe while the cleaning liquid is supplied tothe cup inner wall and/or the base wall surface. Therefore, the cleaningliquid supplied to the cup inner wall and/or the base wall surface isguided to the common pipe through the drain/recovery port of the cup,and then to the drain pipe. Therefore, even if the first chemical liquidor the second chemical liquid adheres to a pipe wall of the common pipein the first chemical liquid supplying step or the second chemicalliquid supplying step, the first chemical liquid or the second chemicalliquid can be washed away from the pipe wall with the cleaning liquidflowing through the common pipe. This reliably prevents the firstchemical liquid and the second chemical liquid from being accidentallybrought into contact with each other or mixed together on the pipe wallof the common pipe. The first chemical liquid may be a sulfuricacid-containing liquid. The second chemical liquid may be an organicsolvent. Examples of the sulfuric acid-containing liquid include SPM andsulfuric acid. Examples of the organic solvent include IPA, methanol,ethanol, HFE (hydrofluoroether) and acetone, at least one of which isused.

According to a third aspect of the present invention, there is provideda substrate treatment apparatus, which includes: a treatment chamber; asubstrate holding mechanism provided in the treatment chamber forholding a substrate; a tubular treatment cup provided in the treatmentchamber and surrounding the substrate holding mechanism; a firstchemical liquid nozzle which spouts a first chemical liquid to thesubstrate held by the substrate holding mechanism; a second chemicalliquid nozzle which spouts a second chemical liquid different from thefirst chemical liquid to the substrate held by the substrate holdingmechanism; a first moving mechanism which moves the first chemicalliquid nozzle between a first outer space and an upper position abovethe substrate held by the substrate holding mechanism, the first outerspace being a predetermined space defined outside the treatment cup inthe treatment chamber as seen in plan; a second moving mechanism whichmoves the second chemical liquid nozzle between a second outer spacedifferent from the first outer space and the upper position above thesubstrate held by the substrate holding mechanism, the second outerspace being a predetermined space defined outside the treatment cup inthe treatment chamber as seen in plan; a first vat disposed at least ina bottom of the first outer space for receiving liquid from above andguiding the liquid toward a first drain port; and a second vat disposedin a bottom of the second outer space for receiving liquid from aboveand guiding the received liquid toward a second drain port differentfrom the first drain port; wherein at least bottom portions of the firstouter space and the second outer space are isolated from each other.

With this arrangement, a vat to be provided on the bottom of thetreatment chamber is divided at least into the first vat disposed in thebottom of the first outer space and the second vat disposed in thebottom of the second outer space. When the first chemical liquid nozzleis moved in the first outer space, the first chemical liquid drippingfrom the first chemical liquid nozzle is received in the first vat. Onthe other hand, when the second chemical liquid nozzle is moved in thesecond outer space, the second chemical liquid dripping from the secondchemical liquid nozzle is received in the second vat. In other words,the vat is divided into the first vat for the first chemical liquid andthe second vat for the second chemical liquid according to the movementranges of the first and second chemical liquid nozzles.

Since at least the bottom portions of the first outer space and thesecond outer space are isolated from each other, there is no liquidcommunication between the first vat and the second vat. Further, theliquid received in the first vat and the liquid received in the secondvat are drained from the different drain ports.

Thus, the first chemical liquid and the second chemical liquid arereliably prevented from being accidentally brought into contact witheach other or mixed together in the vat. Even if the chemical liquids tobe used in combination are inappropriate for mixing thereof, thesubstrate treatment apparatus can reliably prevent the accidental mixingof these chemical liquids in the vat.

The first chemical liquid may be a sulfuric acid-containing liquid. Thesecond chemical liquid may be an organic solvent. Examples of thesulfuric acid-containing liquid include SPM and sulfuric acid. Examplesof the organic solvent include IPA, methanol, ethanol, HFE(hydrofluoroether) and acetone, at least one of which is used.

The foregoing and other objects, features and effects of the presentinvention will become more apparent from the following detaileddescription of the preferred embodiments with reference to the attacheddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a substrate treatment apparatus according to afirst embodiment of the present invention as seen in a horizontaldirection.

FIG. 2 is a sectional view for explaining first and second cleaningnozzles.

FIG. 3 is a sectional view for explaining the first and second cleaningnozzles.

FIG. 4 is a sectional view taken along a sectional plane IV-IV in FIG.1.

FIG. 5 is a sectional view of a boss taken along a sectional plane V-Vin FIG. 4.

FIG. 6 is a process diagram for explaining an exemplary substratetreatment process to be performed by the substrate treatment apparatus.

FIGS. 7A to 7D are schematic diagrams showing the exemplary substratetreatment process.

FIG. 8 is a diagram of a substrate treatment apparatus according to asecond embodiment of the present invention as seen in a horizontaldirection.

FIG. 9 is a diagram showing the inside of a treatment chamber takenalong a sectional plane IX-IX in FIG. 8.

FIG. 10 is a sectional view showing the inside of the treatment chambertaken along a sectional plane X-X in FIG. 8.

FIG. 11 is a sectional view of a first vat taken along a sectional planeXI-XI in FIG. 10.

FIG. 12 is a sectional view taken along a sectional plane XII-XII inFIG. 11.

FIG. 13 is a diagram schematically showing connection between a firsttube and a first drain pipe.

FIG. 14 is a process diagram for explaining another exemplary substratetreatment process to be performed by the substrate treatment apparatusof the second embodiment.

FIG. 15 is a schematic diagram showing the exemplary substrate treatmentprocess.

FIG. 16 is a schematic diagram showing the exemplary substrate treatmentprocess.

FIG. 17 is a schematic diagram showing an upper portion of a treatmentchamber according to a third embodiment of the present invention.

FIG. 18 is a schematic diagram showing a bottom portion of the treatmentchamber shown in FIG. 17.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a diagram of a substrate treatment apparatus 1 according to afirst embodiment of the present invention as seen in a horizontaldirection. FIGS. 2 and 3 are sectional views for explaining first andsecond cleaning nozzles 76, 78. FIG. 2 illustrates a state with a firstguard 44 in opposed relation to a peripheral surface of a substrate W,while FIG. 3 illustrates a state with a fourth guard 47 in opposedrelation to the peripheral surface of the substrate W. FIG. 4 is asectional view taken along a sectional plane IV-IV in FIG. 1. FIG. 5 isa sectional view of a boss 21 taken along a sectional plane V-V in FIG.4.

The substrate treatment apparatus 1 is of a single substrate treatmenttype adapted to treat a front surface (having a device formation region)of a substrate W (e.g., a round semiconductor wafer or the like) with aliquid for a cleaning process or an etching process. The substratetreatment apparatus 1 includes a box-shaped treatment chamber 2 havingan inside space, a spin chuck (substrate holding and rotating mechanism)3 which horizontally holds a single substrate W in the treatment chamber2 and rotates the substrate W about a vertical rotation axis A1extending through the center of the substrate W, a sulfuricacid-containing liquid supplying unit (first chemical liquid supplyingunit) 4 which supplies a sulfuric acid/hydrogen peroxide mixture (SPM)as an exemplary sulfuric acid-containing liquid (first chemical liquid)to the substrate W held by the spin chuck 3, an organic solventsupplying unit (second chemical liquid supplying unit) 5 which suppliesisopropyl alcohol (IPA) as an exemplary organic solvent (organic solventhaving a lower surface tension, second chemical liquid) to the frontsurface (upper surface) of the substrate W held by the spin chuck 3, arinse liquid supplying unit 6 which supplies DIW (deionized water) as anexemplary rinse liquid to the front surface (upper surface) of thesubstrate W held by the spin chuck 3, a tubular treatment cup 7surrounding the spin chuck 3, and a controller 8 which controls theoperations of devices provided in the substrate treatment apparatus 1and the opening and closing of valves.

The treatment chamber 2 includes a boxed-shaped partition wall 10, anFFU (fan filter unit) 11 as an air supplying unit which supplies cleanair into the inside of the partition wall 10 (into the treatment chamber2) from above the partition wall 10, and an evacuation unit (not shown)which expels gas from the treatment chamber 2 from below the partitionwall 10. The spin chuck 3, a sulfuric acid-containing liquid nozzle 27of the sulfuric acid-containing liquid supplying unit 4, an organicsolvent nozzle 33 of the organic solvent supplying unit 5, and a rinseliquid nozzle 39 of the rinse liquid supplying unit 6 are accommodatedin the inside of the partition wall 10.

The FFU 11 is disposed on the partition wall 10, and attached to a topportion of the partition wall 10. The FFU 11 supplies the clean air intothe treatment chamber 2 from the top portion of the partition wall 10.The evacuation unit is connected to a bottom portion of the treatmentcup 7 through a cup evacuation duct 49, and the inside of the treatmentcup 7 is evacuated through the bottom portion of the treatment cup 7.The FFU 11 and the evacuation unit forma down flow (downward stream) inthe treatment chamber 2.

A chuck of a clamping type adapted to horizontally clamp the substrate Wto horizontally hold the substrate W is used as the spin chuck 3. Morespecifically, the spin chuck 3 includes a spin motor 13, a spin shaft 14unified with a drive shaft of the spin motor 13, a disk-shaped spin base15 horizontally attached to an upper end of the spin shaft 14, and acover member 17 which covers the periphery of the spin motor 13 and thespin shaft 14 to define a side wall of the spin chuck excluding the spinbase 15.

The spin shaft 14 is a vertical hollow shaft, in which a lower surfacesupply line (not shown) is inserted. A treatment liquid (e.g., firstchemical liquid, second chemical liquid or pure water (DIW)) is suppliedto the lower surface supply line. A lower surface nozzle 18 which spoutsthe treatment liquid supplied to the lower surface supply line isprovided at an upper end of the lower surface supply line. The lowersurface nozzle 18 spouts the treatment liquid generally verticallyupward, and the treatment liquid spouted from the lower surface nozzle18 is applied generally perpendicularly to a center portion of a lowersurface of the substrate W held by the spin chuck 3.

The spin motor 13 is disposed on a horizontal bottom plate 19, andsurrounded by the tubular cover member 17. The cover member 17 has alower edge disposed on the bottom plate 19 of the partition wall 10, andan upper edge portion extending to near the spin base 15.

As shown in FIGS. 1 and 4, a plurality of clamping members 16 (three ormore clamping members, e.g., six clamping members) are circumferentiallyprovided on an upper surface of the spin base 15. The clamping members16 are disposed in circumferentially properly spaced relation accordingto the outer peripheral shape of the substrate W on a peripheral portionof the upper surface of the spin base 15. In FIG. 4, the substrate W isnot held on the spin chuck 3.

As shown in FIG. 1, the cover member 17 includes a cylindrical base boss20, a cylindrical boss 21 and an annular disk-shaped boss cover 22,which are combined together in this order from a lower side. The baseboss 20 and the boss 21 are fixed to each other by bolts (not shown),and the boss 21 and the boss cover 22 are fixed to each other by bolts(not shown). The base boss 20 is disposed on the bottom plate 19 tosurround the spin motor 13. The boss cover 22 fills a gap definedbetween the spin base 15 and the boss 21.

As shown in FIG. 5, the boss 21 integrally includes a lower portion 23having a first cylindrical surface 23A serving as an outer peripheralsurface thereof, a middle portion 24 having an upwardly projectingconical taper surface 24A serving as an outer peripheral surface thereofand an upper portion 25 having a second cylindrical surface 25A servingas an outer peripheral surface thereof, and is made of a resin materialsuch as PVC (polyvinyl chloride).

As shown in FIG. 1, the sulfuric acid-containing liquid supplying unit 4includes a sulfuric acid-containing liquid nozzle 27 which spouts theSPM toward the front surface of the substrate W, a first nozzle arm 28having a distal end to which the sulfuric acid-containing liquid nozzle27 is attached, a first arm support shaft 29 extending vertically on alateral side of the spin chuck 3 and pivotally supporting the firstnozzle arm 28, and a first arm pivoting unit 30 which rotates the firstarm support shaft 29 to move the first nozzle arm 28 to thereby move thesulfuric acid-containing liquid nozzle 27. The sulfuric acid-containingliquid nozzle 27 is, for example, a straight nozzle which spouts the SPMin the form of continuous stream, and is attached to the horizontalfirst nozzle arm 28, for example, with its spout directed downward. Thefirst nozzle arm 28 extends horizontally.

The sulfuric acid-containing liquid supplying unit 4 further includes asulfuric acid-containing liquid line 31 through which the SPM is guidedto the sulfuric acid-containing liquid nozzle 27, and a sulfuricacid-containing liquid valve 32 which opens and closes the sulfuricacid-containing liquid line 31. With the sulfuric acid-containing liquidvalve 32 open, the SPM is supplied from an SPM supply source to thesulfuric acid-containing liquid nozzle 27 through the sulfuricacid-containing liquid line 31. Thus, the SPM is spouted from thesulfuric acid-containing liquid nozzle 27.

The first arm pivoting unit 30 pivots the first nozzle arm 28 about thefirst arm support shaft 29, whereby the sulfuric acid-containing liquidnozzle 27 is horizontally moved. The first arm pivoting unit 30horizontally moves the sulfuric acid-containing liquid nozzle 27 betweena treatment position such that the SPM spouted from the sulfuricacid-containing liquid nozzle 27 is applied to the upper surface of thesubstrate W and a home position at which the sulfuric acid-containingliquid nozzle 27 is located adjacent the spin chuck 3 as seen in plan.Further, the first arm pivoting unit 30 horizontally moves the sulfuricacid-containing liquid nozzle 27 between a center position such that theSPM spouted from the sulfuric acid-containing liquid nozzle 27 isapplied to the upper surface center portion of the substrate W and aperipheral position such that the SPM spouted from the sulfuricacid-containing liquid nozzle 27 is applied to the upper surfaceperipheral portion of the substrate W. The center position and theperipheral position are each defined as the treatment position. Thesulfuric acid-containing liquid nozzle 27 may be a fixed nozzle which isfixedly disposed with its spout directed toward a predetermined position(e.g., center portion) on the upper surface of the substrate W.

The organic solvent supplying unit 5 includes an organic solvent nozzle33 which spouts IPA toward the front surface of the substrate W, asecond nozzle arm 34 having a distal end to which the organic solventnozzle 33 is attached, a second arm support shaft 35 extendingvertically on a lateral side of the spin chuck 3 and pivotallysupporting the second nozzle arm 34, and a second arm pivoting unit 36which rotates the second arm support shaft 35 to move the second nozzlearm 34 to thereby move the organic solvent nozzle 33. The organicsolvent nozzle 33 is, for example, a straight nozzle which spouts IPA inthe form of continuous stream, and is attached to the horizontal secondnozzle arm 34, for example, with its spout directed downward. The secondnozzle arm 34 extends horizontally.

The organic solvent supplying unit 5 further includes an organic solventline 37 through which IPA is guided to the organic solvent nozzle 33,and an organic solvent valve 38 which opens and closes the organicsolvent line 37. With the organic solvent valve 38 open, IPA is suppliedfrom an IPA supply source to the organic solvent nozzle 33 through theorganic solvent line 37. Thus, IPA is spouted from the organic solventnozzle 33.

The second arm pivoting unit 36 pivots the second nozzle arm 34 aboutthe second arm support shaft 35, whereby the organic solvent nozzle 33is horizontally moved. The second arm pivoting unit 36 horizontallymoves the organic solvent nozzle 33 between a treatment position suchthat IPA spouted from the organic solvent nozzle 33 is applied to theupper surface of the substrate W and a home position at which theorganic solvent nozzle 33 is located adjacent the spin chuck 3 as seenin plan. Further, the second arm pivoting unit 36 horizontally moves theorganic solvent nozzle 33 between a center position such that IPAspouted from the organic solvent nozzle 33 is applied to the uppersurface center portion of the substrate W and a peripheral position suchthat IPA spouted from the organic solvent nozzle 33 is applied to theupper surface peripheral portion of the substrate W. The center positionand the peripheral position are each defined as the treatment position.The organic solvent nozzle 33 may be a fixed nozzle which is fixedlydisposed with its spout directed toward a predetermined position (e.g.,center portion) on the upper surface of the substrate W.

The rinse liquid supplying unit 6 includes a rinse liquid nozzle 39which spouts the rinse liquid toward the substrate W held by the spinchuck 3, a rinse liquid line 40 which supplies the rinse liquid to therinse liquid nozzle 39, and a rinse liquid valve 41 which switches onand off the supply of the rinse liquid from the rinse liquid line 40 tothe rinse liquid nozzle 39. The rinse liquid nozzle 39 is a fixed nozzlewhich spouts the rinse liquid with its spout kept still. The rinseliquid supplying unit 6 may include a rinse liquid nozzle moving devicewhich moves the rinse liquid nozzle 39 to move a rinse liquidapplication position on the upper surface of the substrate W.

With the rinse liquid valve 41 open, the rinse liquid supplied from therinse liquid line 40 to the rinse liquid nozzle 39 is spouted from therinse liquid nozzle 39 toward the upper surface center portion of thesubstrate W. The rinse liquid is pure water (deionized water) by way ofexample not by way of limitation. Other examples of the rinse liquidinclude carbonated water, electrolytic ion water, hydrogen water, ozonewater and a hydrochloric acid aqueous solution having a diluteconcentration (e.g., about 10 to about 100 ppm).

The treatment cup 7 includes a cylindrical member 50 surrounding thespin chuck 3, a plurality of cups 42, 43 (first and second cups 42, 43)fixedly provided between the spin chuck 3 and the cylindrical member 50,a plurality of guards 44 to 47 (first to fourth guards 44 to 47) whicheach receive a treatment liquid (chemical liquid and rinse liquid)scattered around the substrate W, and a guard lift unit 48 whichindependently moves up and down the respective guards 44 to 47. Bydriving the guard lift unit 48, the guards 44 to 47 are independentlymoved up and down. The guard lift unit 48 includes, for example, a ballscrew mechanism.

The cylindrical member 50 surrounds the spin chuck 3. The cylindricalmember 50 is configured to retain the treatment liquid therein. Thetreatment liquid retained in the cylindrical member 50 is guided to adrain unit (not shown). An upstream end of the cup evacuation duct 49 isconnected to a predetermined circumferential portion of a lower edgeportion of the cylindrical member 50. A downstream end of the cupevacuation duct 49 is connected to the evacuation unit (not shown)provided outside the apparatus. An internal atmosphere of thecylindrical member 50 is expelled through the cup evacuation duct 49 bythe evacuation unit (not shown). A third cup 74 is disposed along aninner periphery of the cylindrical member 50 to surround the first tofourth guards 44 to 47. The third cup 74 has a U-shaped cross section todefine a drain channel 75 for collecting and draining a treatment liquidused for the treatment of the substrate W. The treatment liquidcollected in the drain channel 75 is guided to the drain unit (notshown).

The treatment cup 7 is collapsible, and the guard lift unit 48 moves upand down at least one of the four guards 44 to 47, whereby the treatmentcup 7 is expanded and collapsed.

The first cup 42 has an annular shape, and surrounds the spin chuck 3between the spin chuck 3 and the cylindrical member 50. The first cup 42is generally rotationally symmetrical about the rotation axis A1 of thesubstrate W. The first cup 42 integrally includes an annular bottom 51(see FIGS. 2 and 3) as seen in plan, a cylindrical inner wall 52 (seeFIG. 2 and the like) extending upright from an inner peripheral edge ofthe bottom 51, and a cylindrical outer wall 53 (see FIG. 2 and the like)extending upright from an outer peripheral edge of the bottom 51. Thebottom 51, the inner wall 52 and the outer wall 53 forma U-shaped crosssection. The bottom 51, the inner wall 52 and the outer wall 53 define afirst drain/recovery channel 54 (see FIG. 2 and the like) for recoveringor draining the treatment liquid used for the treatment of the substrateW. The first drain/recovery channel 54 has a first drain/recovery port92 (see FIG. 4) which opens in a lowermost bottom portion thereof. Afirst common pipe 93 is connected to the first drain/recovery port 92.The first common pipe 93 is branched to be connected to a first recoverypipe 95 and a first drain pipe 96. A first recovery valve 95A isprovided in the first recovery pipe 95, and a first drain valve 96A isprovided in the first drain pipe 96. By opening the first recovery valve95A with the first drain valve 96A closed, liquid flowing through thefirst common pipe 93 is guided to the first recovery pipe 95 (recoveryport (see FIG. 7A and the like)). By opening the first drain valve 96Awith the first recovery valve 95A closed, the liquid flowing through thefirst common pipe 93 is guided to the first drain pipe 96 (drain port(see FIG. 7A and the like)). That is, the first recovery valve 95A andthe first drain valve 96A function as switch valves which switch thedestination of the liquid flowing through the first common pipe 93between the first recovery pipe 95 and the first drain pipe 96.

A distal end portion of the first recovery pipe 95 extends to a recoverytreatment unit (not shown), and a distal end portion of the firstdrainpipe 96 extends to the drain unit (not shown). By switching thedestination by units of the switch valves (the first recovery valve 95Aand the first drain valve 96A), the liquid flowing through the firstcommon pipe 93 is selectively guided to the first recovery pipe 95 andthe first drain pipe 96. Thus, the treatment liquid expelled from thesubstrate W is recovered or drained.

The second cup 43 has an annular shape, and surrounds the spin chuck 3between the first cup 42 and the cylindrical member 50. The second cup43 is generally rotationally symmetrical about the rotation axis A1 ofthe substrate W. The second cup 43 has a U-shaped cross section, anddefines a second drain/recovery channel 55 (see FIG. 2 and the like) forcollecting and recovering the treatment liquid used for the treatment ofthe substrate W. The second drain/recovery channel 55 has a seconddrain/recovery port 97 which opens in a lowermost bottom portionthereof. A second common pipe 98 is connected to the seconddrain/recovery port 97. The second common pipe 98 is branched to beconnected to a second recovery pipe 100 and a second drain pipe 101. Asecond recovery valve 100A is provided in the second recovery pipe 100,and a second drain valve 101A is provided in the second drain pipe 101.By opening the second recovery valve 100A with the second drain valve101A closed, liquid flowing through the second common pipe 98 is guidedto the second recovery pipe 100. By opening the second drain valve 101Awith the second recovery valve 100A closed, the liquid flowing throughthe second common pipe 98 is guided to the second drain pipe 101. Thatis, the second recovery valve 100A and the second drain valve 101Afunction as switch valves which switch the destination of the liquidflowing through the second common pipe 98 between the second recoverypipe 100 and the second drain pipe 101. A distal end portion of thesecond recovery pipe 100 extends to the recovery treatment unit (notshown), and a distal end portion of the second drain pipe 101 extends tothe drain unit (not shown). By switching the destination by units of theswitch valves (the second recovery valve 100A and the second drain valve101A), the liquid flowing through the second common pipe 98 isselectively guided to the second recovery pipe 100 and the second drainpipe 101.

A third drain/recovery port 102 opens in a lowermost bottom portion of athird drain/recovery channel 66. A third common pipe 103 is connected tothe third drain/recovery port 102. The third common pipe 103 is branchedto be connected to a third recovery pipe 105 and a third drain pipe 106.A third recovery valve 105A is provided in the third recovery pipe 105,and a third drain valve 106A is provided in the third drain pipe 106. Byopening the third recovery valve 105A with the third drain valve 106Aclosed, liquid flowing through the third common pipe 103 is guided tothe third recovery pipe 105. By opening the third drain valve 106A withthe third recovery valve 105A closed, the liquid flowing through thethird common pipe 103 is guided to the third drain pipe 106. That is,the third recovery valve 105A and the third drain valve 106A function asswitch valves which switch the destination of the liquid flowing throughthe third common pipe 103 between the third recovery pipe 105 and thethird drain pipe 106. A distal end portion of the third recovery pipe105 extends to the recovery treatment unit (not shown), and a distal endportion of the third drain pipe 106 extends to the drain unit (notshown). By switching the destination by means of the switch valves (thethird recovery valve 105A and the third drain valve 106A), the liquidflowing through the third common pipe 103 is selectively guided to thethird recovery pipe 105 and the third drain pipe 106.

The innermost first guard 44 surrounds the spin chuck 3, and isgenerally rotationally symmetrical about the rotation axis A1 of thesubstrate W rotated by the spin chuck 3. The first guard 44 integrallyincludes a cylindrical guide portion 56 surrounding the spin chuck 3,and a cylindrical treatment liquid separation wall 57 connected to theguide portion 56. The guide portion 56 includes a cylindrical lowerportion 58 (see FIG. 2 and the like) surrounding the spin chuck 3, acylindrical thicker portion 59 (see FIG. 2 and the like) extendingoutward from an upper edge of the lower portion 58 (away from therotation axis A1 of the substrate W), a cylindrical middle portion 60(see FIG. 2 and the like) extending vertically upward from an outerperiphery of an upper surface of the thicker portion 59, and an annularupper portion 61 (see FIG. 2 and the like) extending obliquely upwardinward (toward the rotation axis A1 of the substrate W) from an upperedge of the middle portion 60.

The treatment liquid separation wall 57 slightly extends verticallydownward from the outer periphery of the thicker portion 59, and islocated above the second drain/recovery channel 55 (see FIG. 2 and thelike). The lower portion 58 of the guide portion 56 is located above thefirst drain/recovery channel 54 (see FIG. 2 and the like), and isaccommodated in the first drain/recovery channel 54 when the first guard44 and the first cup 42 are located closest to each other. An innerperipheral edge of the upper portion 61 has a round shape having agreater diameter than the substrate W held by the spin chuck 3 as seenin plan. The upper portion 61 may have a linear sectional shape as shownin FIG. 1 and the like, or may have a gradual arcuate shape, forexample.

The second guard 45 located at the second innermost position isgenerally rotationally symmetrical about the rotation axis A1 of thesubstrate W around the first guard 44. The second guard 45 integrallyincludes a guide portion 62, and a cup portion 63 provided outside theguide portion 62.

The guide portion 62 includes a cylindrical portion 64 (see FIG. 2 andthe like) provided outside the middle portion 60 of the first guard 44coaxially with the middle portion 60, and an upper portion 65 (see FIG.2 and the like) extending obliquely upward toward the center from anupper edge of the cylindrical portion 64 (toward the rotation axis A1 ofthe substrate W). The cylindrical portion 64 is located above the seconddrain/recovery channel 55, and is accommodated in the seconddrain/recovery channel 55 when the second guard 45 and the second cup 43are located closest to each other. An inner peripheral edge of the upperportion 65 has a round shape having a greater diameter than thesubstrate W held by the spin chuck 3 as seen in plan. The upper portion65 may have a linear sectional shape as shown in FIG. 1 and the like, ormay have a gradual arcuate shape, for example.

The cup portion 63 is connected to an outer periphery of the upperportion 65 of the guide portion 62. The cup portion 63 is disposedbetween the second cup 43 and the cylindrical member 50 as seen in plan.The cup portion 63 is generally rotationally symmetrical about therotation axis A1 of the substrate W. The cup portion 63 has a U-shapedsectional shape, and defines a third drain/recovery channel 66 (see FIG.2 and the like) for collecting and recovering the treatment liquid usedfor the treatment of the substrate W. The treatment liquid collected inthe third drain/recovery channel 66 is sent to the recovery treatmentunit (not shown) or the drain unit (not shown).

The third guard 46 located at the third innermost position is generallyrotationally symmetrical about the rotation axis A1 of the substrate Wrotated by the spin chuck 3. The third guard 46 surrounds the spin chuck3. The third guard 46 integrally includes a cylindrical lower portion 68(see FIG. 2 and the like) surrounding the second guard 45, an annularupper portion 69 (see FIG. 2 and the like) extending obliquely upwardinward from an upper edge of the lower portion 68, a suspended portion70 (see FIG. 2 and the like) extending vertically downward from an outerperipheral edge of the upper portion 69, and a projection 71 (see FIG. 2and the like) projecting outward from a middle portion of the suspendedportion 70 and having an outer peripheral portion extending verticallydownward. The lower portion 68 is located above the third drain/recoverychannel 66, and is accommodated in the third drain/recovery channel 66when the second guard 45 and the third guard 46 are located closest toeach other. The projection 71 is located above the drain channel 75, andis accommodated in the drain channel 75 when the third guard 46 islocated at a lower position. An inner peripheral edge of the upperportion 69 has a round shape having a greater diameter than thesubstrate W held by the spin chuck 3 as seen in plan. The upper portion69 may have a linear sectional shape as shown in FIG. 1 and the like, ormay have a gradual arcuate shape, for example.

The outermost fourth guard 47 surrounds the spin chuck 3 outside thethird guard 46, and is generally rotationally symmetrical about therotation axis A1 of the substrate W rotated by the spin chuck 3. Thefourth guard 47 includes a cylindrical portion 72 coaxial with the thirdguard 46, and an upper portion 73 extending obliquely upward toward thecenter (toward the rotation axis A1 of the substrate W) from an upperedge of the cylindrical portion 72. The cylindrical portion 72 islocated above the projection 71 of the third guard 46. An innerperipheral edge of the upper portion 73 has a round shape having agreater diameter than the substrate W held by the spin chuck 3. Theupper portion 73 may have a linear sectional shape as shown in FIG. 1and the like, or may have a gradual arcuate shape, for example.

As shown in FIG. 1, the guard lift unit 48 moves up and down therespective guards 44 to 47 between an upper position such that the guardupper edge is located above the substrate W and a lower position suchthat the guard upper edge is located below the substrate W. The guardlift unit 48 can retain each of the guards 44 to 47 at a desiredposition between the upper position and the lower position. When thetreatment liquid is supplied to the substrate W or when the substrate Wis dried, any one of the guards 44 to 47 is opposed to the peripheralsurface of the substrate W.

Where the innermost first guard 44 is opposed to the peripheral surfaceof the substrate W, as shown in FIG. 2, all the first to fourth guards44 to 47 are located at the upper position. In this state, a lower edgeof the lower portion 58 of the first guard 44 is located at the samelevel as an upper edge of the first drain/recovery channel 54. That is,only the distal edge of the lower portion 58 of the first guard 44enters the first drain/recovery channel 54.

Where the second guard 45 located at the second innermost position isopposed to the peripheral surface of the substrate W, the second tofourth guards 45 to 47 are each located at the upper position (theposition shown in FIG. 2), and the first guard 44 is located at thelower position (the position shown in FIG. 3).

Where the third guard 46 located at the third innermost position isopposed to the peripheral surface of the substrate W, the third andfourth guards 46, 47 are each located at the upper position (theposition shown in FIG. 2), and the first and second guards 44, 45 areeach located at the lower position (the position shown in FIG. 3).

Where the outermost fourth guard 47 is opposed to the peripheral surfaceof the substrate W, as shown in FIG. 3, the fourth guard 47 is locatedat the upper position, and the first to third guards 44 to 46 are eachlocated at the lower position.

The substrate treatment apparatus 1 further includes a first cleaningliquid nozzle 76 which spouts the cleaning liquid toward a peripheralsurface and a bottom surface (base wall surface) of an outer periphery15A of the spin base 15, a first cleaning liquid supplying unit 77 whichsupplies the cleaning liquid to the first cleaning liquid nozzle 76, asecond cleaning liquid nozzle 78 which supplies the cleaning liquid toan inner wall of the first cup 42 (cup inner wall), and a secondcleaning liquid supplying unit 79 which supplies the cleaning liquid tothe second cleaning liquid nozzle 78. The first and second cleaningliquid nozzles 76, 78 each include a plurality of cleaning liquidnozzles (e.g., the first cleaning liquid nozzle 76 includes two firstcleaning liquid nozzles 76, and the second cleaning liquid nozzle 78includes four second cleaning liquid nozzles 78).

The cleaning liquid is pure water (deionized water) by way of examplebut not by way of limitation. A cleaning chemical liquid (e.g., SC1 (aliquid mixture of NH₄OH and H₂O₂) may be used.

The first cleaning nozzles 76 each have a single first cleaning liquidoutlet port 80 (see FIG. 5) which is opposed to the peripheral surfaceand the bottom surface of the outer periphery 15A. As shown in FIG. 5,the first cleaning liquid outlet port 80 is directed obliquely upwardradially inward of the spin base 15. The two first cleaning liquidoutlet ports 80 are located in an upper portion of the taper surface 24Aof the boss 21. That is, the two first cleaning liquid outlet ports 80are located obliquely below the outer periphery 15A of the spin base 15.The two first cleaning liquid outlet ports 80 are located at the sameheight, more specifically, in diametrically opposed relation about thecenter (rotation axis A1) of the spin base 15 as shown in FIG. 4.

The second cleaning liquid nozzles 78 each have a single second cleaningliquid outlet port 81 (see FIG. 5). As shown in FIG. 5, the four secondcleaning liquid outlet ports 81 are located at the same height in theupper portion of the taper surface 24A of the boss 21. The secondcleaning liquid outlet ports 81 are disposed obliquely below the spinbase 15 radially outward of the spin base 15. As shown in FIG. 4, thefour second cleaning liquid outlet ports 81 are spaced a predetermineddistance from each other circumferentially of the spin base 15 so as tobe symmetrical with respect to a phantom line A2 extending between thefirst drain/recovery port 92 and the center (rotation axis A1) of thespin base 15. The second cleaning liquid nozzles 78 are absent in acircumferential region of the boss 21 near the first drain/recovery port92.

As shown in FIG. 5, the first cleaning liquid supplying unit 77 includesa first cleaning liquid flow passage 82 provided inside the boss 21, afirst cleaning liquid supply line 83 which supplies the cleaning liquidto the first cleaning liquid flow passage 82, and a first cleaningliquid valve 84 which opens and closes the first cleaning liquid supplyline 83. The first cleaning liquid flow passage 82 includes a firstcommon flow passage 85 extending semi-circumferentially and having arectangular cross section (also see FIG. 4), and a plurality of firstbranch flow passages 86 which connect the first common flow passage 85to the first cleaning liquid outlet ports 80, respectively. The firstbranch flow passages 86 extend vertically upward from the first commonflow passage 85 and are then bent obliquely upward to open in the tapersurface 24A of the boss 21 to thereby define the first cleaning liquidoutlet ports 80.

As shown in FIG. 5, the second cleaning liquid supplying unit 79includes a second cleaning liquid flow passage 87 provided inside theboss 21, a second cleaning liquid supply line 88 which supplies thecleaning liquid to the second cleaning liquid flow passage 87, and asecond cleaning liquid valve 89 which opens and closes the secondcleaning liquid supply line 88. The second cleaning liquid flow passage87 includes a second common flow passage 90 having a rectangular crosssection and extending in an arcuate configuration having the samediameter as the first common flow passage 85 and coaxial with the firstcommon flow passage 85 (also see FIG. 4), and a plurality of secondbranch flow passages 91 which connect the second common flow passage 90to the second cleaning liquid outlet ports 81, respectively. The secondcommon flow passage 90 is provided at the same height as the firstcommon flow passage 85 in non-overlapping relation with the first commonflow passage 85 circumferentially of the spin base 15. The second branchflow passages 91 extend vertically upward from the second common flowpassage 90 and are then bent obliquely downward to open in the tapersurface 24A of the boss 21 to thereby define the second cleaning liquidoutlet ports 81.

FIG. 6 is a process diagram for explaining an exemplary resist removingprocess to be performed on the substrate W by the substrate treatmentapparatus 1. FIGS. 7A to 7D are schematic diagrams showing the exemplaryresist removing process.

Referring to FIGS. 1 and 6, the exemplary resist removing process willhereinafter be described. Reference will also be made to FIGS. 2 to 5and FIGS. 7A to 7D.

When the resist removing process is to be performed by the substratetreatment apparatus 1, a substrate W subjected to a high-dose ionimplantation process is loaded into the treatment chamber 2 (Step S1).The substrate W to be loaded is not subjected to a resist ashingprocess. The substrate W has a front surface formed with a minutepattern having a higher-aspect ratio. More specifically, the controller8 retracts all the nozzles and the like from above the spin chuck 3, andmoves the first to fourth guards 44 to 47 to the lower position (thelowermost position). While the upper edges of the first to fourth guards44 to 47 are located below a substrate holding position at which thesubstrate W is to be held by the spin chuck 3, hands (not shown) of asubstrate transport robot (not shown) are moved into the treatmentchamber 2 with the substrate W held thereon, whereby the substrate W istransferred to the spin chuck 3 with its front surface facing up.

Thereafter, the controller 8 controls the guard lift unit 48 to move thefirst to fourth guards 44 to 47 to the upper position (the uppermostposition) to bring the first guard 44 into opposed relation to theperipheral surface of the substrate W.

Then, the controller 8 causes the spin motor 13 to start rotating thesubstrate W (Step S2). The rotation speed of the substrate W isincreased to a predetermined sulfuric acid-containing liquid treatmentspeed (100 to 500 rpm, e.g., about 300 rpm) and maintained at thesulfuric acid-containing liquid treatment speed. The controller 8controls the first recovery valve 95A and the first drain valve 96A toset the destination of the liquid flowing through the first common pipe93 to the first recovery pipe 95.

After the rotation speed of the substrate W reaches the sulfuricacid-containing liquid treatment speed, the controller 8 performs asulfuric acid-containing liquid supplying step of supplying the SPM tothe substrate W (first chemical liquid supplying step, Step S3). Morespecifically, the controller 8 controls the first arm pivoting unit 30to move the sulfuric acid-containing liquid nozzle 27 from the homeposition to the treatment position. Thus, the sulfuric acid-containingliquid nozzle 27 is located above the substrate W.

After the sulfuric acid-containing liquid nozzle 27 is located above thesubstrate W, the controller 8 opens the sulfuric acid-containing liquidvalve 32, whereby the SPM is spouted from the spout of the sulfuricacid-containing liquid nozzle 27 to be applied to the upper surface ofthe substrate W as shown in FIG. 7A. The controller 8 controls the firstarm pivoting unit 30 to move the SPM application position between thecenter portion and the peripheral portion of the upper surface of thesubstrate W at this state.

After the SPM spouted from the sulfuric acid-containing liquid nozzle 27is applied to the upper surface of the substrate W rotated at thesulfuric acid-containing liquid treatment speed (e.g., 300 rpm), the SPMreceives a centrifugal force to flow outward on the upper surface of thesubstrate W. Therefore, the SPM is supplied to the entire upper surfaceof the substrate W, whereby a liquid film of the SPM is formed on thesubstrate W as covering the entire upper surface of the substrate W. Theresist on the substrate W is removed from the substrate W by a chemicalreaction between the resist and the SPM. The controller 8 moves the SPMapplication position between the center portion and the peripheralportion of the upper surface of the substrate W, while rotating thesubstrate W. Thus, the SPM application position passes over the entireupper surface of the substrate W, whereby the entire upper surface ofthe substrate W is scanned with the SPM application position. Therefore,the SPM spouted from the sulfuric acid-containing liquid nozzle 27 issupplied to the entire upper surface of the substrate W to evenly treatthe entire upper surface of the substrate W. The SPM supplied to theupper surface of the substrate W is scattered from the periphery of thesubstrate W laterally of the substrate W.

The SPM scattered from the periphery of the substrate W is received bythe inner wall of the first guard 44. The chemical liquid flows down onthe inner wall of the first guard 44, and is received by the first cup42 and collected in a bottom portion of the first cup 42 to be guided tothe first common pipe 93. At this time, the destination of the liquidflowing through the first common pipe 93 is set to the first recoverypipe 95 by the first recovery valve 95A and the first drain valve 96A,so that the SPM guided to the first common pipe 93 is further guided tothe recovery treatment unit (not shown) through the first recovery pipe95. After the sulfuric acid-containing liquid supplying step (S3), theSPM adheres to the inner wall of the first cup 42, the peripheralsurface and the bottom surface of the outer periphery 15A and the pipewall of the first common pipe 93.

After a lapse of a predetermined period from the start of the spoutingof the SPM, the controller 8 closes the sulfuric acid-containing liquidvalve 32 to stop spouting the SPM. Further, the controller 8 controlsthe first arm pivoting unit 30 to move the sulfuric acid-containingliquid nozzle 27 from the treatment position to the home position.

After the end of the sulfuric acid-containing liquid supplying step(S3), a rinsing step of supplying the rinse liquid to the substrate W(Step S4) is performed with the first guard 44 opposed to the peripheralsurface of the substrate W. More specifically, the controller 8 controlsthe first recovery valve 95A and the first drain valve 96A to switch thedestination of the liquid flowing through the first common pipe 93 tothe first drain pipe 96. Further, the controller 8 opens the rinseliquid valve 41 to spout the rinse liquid from the rinse liquid nozzle39 toward the upper surface center portion of the substrate W as shownin FIG. 7B.

The rinse liquid spouted from the rinse liquid nozzle 39 is applied tothe upper surface center portion of the substrate W covered with the SPMliquid film, and receives a centrifugal force generated by the rotationof the substrate W to flow toward the periphery of the substrate W onthe upper surface of the substrate W. Thus, the SPM on the substrate Wis forced to flow outward by the rinse liquid to be expelled around thesubstrate W. Therefore, the SPM liquid film on the substrate W isreplaced with a liquid film of the rinse liquid covering the entireupper surface of the substrate W. Thus, the SPM is rinsed away from theentire upper surface of the substrate W. The rinse liquid supplied tothe upper surface of the substrate W is scattered from the periphery ofthe substrate W laterally of the substrate W.

The rinse liquid scattered from the periphery of the substrate W isreceived by the inner wall of the first guard 44. The rinse liquid flowsdown on the inner wall of the first guard 44, and then drips from thelower edge of the lower portion 58 to be received in the first cup 42.The rinse liquid supplied to the first cup 42 moves circumferentially ofthe first cup 42 toward the first drain/recovery port 92 in the firstcup 42 to be guided to the first common pipe 93 from the firstdrain/recovery port 92. Since the destination of the liquid flowingthrough the first common pipe 93 is set to the first drain pipe 96, therinse liquid guided to the first common pipe 93 is further guided to thedrain unit (not shown) through the first drain pipe 96.

In the rinsing step (S4), as shown in FIGS. 2 and 7B, the controller 8opens the first cleaning liquid valve 84 and the second cleaning liquidvalve 89 to spout the cleaning liquid from the first cleaning liquidoutlet ports 80 of the first cleaning liquid nozzles 76 (see FIG. 5) andthe second cleaning liquid outlet ports 81 of the second cleaning liquidnozzles 78 (see FIG. 5) (first cleaning liquid supplying step).

As shown in FIG. 2, the cleaning liquid spouted from the first cleaningliquid nozzles 76 is sprayed onto the peripheral surface and the bottomsurface of the outer periphery 15A. Thus, the SPM is washed away fromthe peripheral surface and the bottom surface of the outer periphery15A. The cleaning liquid spouted from the first cleaning liquid nozzles76 is splashed on the wall surface of the outer periphery 15A to beapplied to inner wall portions (e.g., the inner walls of the middleportion 60 and the thicker portion 59) of the first guard 44. Then, thecleaning liquid flows down on the inner wall of the lower portion 58 ofthe first guard 44, and drips from the lower edge of the lower portion58 to be received in the first drain/recovery channel 54 of the firstcup 42. The cleaning liquid spouted from the second cleaning liquidoutlet ports 81 is sprayed onto a vertically middle inner wall portionof the lower portion 58 of the first guard 44 to flow down on the innerwall of the lower portion 58. Then, the cleaning liquid drips from thelower edge of the lower portion 58 to be received in the firstdrain/recovery channel 54 of the first cup 42. As indicated by arrows inFIG. 4, the cleaning liquid supplied to the first drain/recovery channel54 moves circumferentially of the first cup 42 toward the firstdrain/recovery port 92 in the first drain/recovery channel 54 to beguided to the first common pipe 93 from the first drain/recovery port92. Since the destination of the liquid flowing through the first commonpipe 93 is set to the first drainpipe 96, the cleaning liquid guided tothe first common pipe 93 is further guided to the drain unit (not shown)through the first drain pipe 96 to be drained. The cleaning liquid flowsin the first cup 42 and the first common pipe 93, whereby the inner wallof the first cup 42 and the pipe wall of the first common pipe 93 arecleaned.

In the rinsing step (S4), the rinse liquid is scattered on theperipheral surface and the bottom surface of the outer periphery 15A,and the rinse liquid received by the first guard 44 flows on the innerwall of the first cup 42 and on the pipe wall of the first common pipe93. Thus, the SPM adhering to the inner wall of the first cup 42, theperipheral surface and the bottom surface of the outer periphery 15A andthe pipe wall of the first common pipe 93 is considered to be rinsedaway with the rinse liquid after the sulfuric acid-containing liquidsupplying step (S3). However, the rinsing with the rinse liquid in therinsing step (S4) alone is considered to be insufficient because the SPMpartly remains on the inner wall of the first cup 42, the peripheralsurface and the bottom surface of the outer periphery 15A and the pipewall of the first common pipe 93.

In this exemplary process, the first cleaning liquid supplying step isperformed in the rinsing step (S4). Thus, the SPM adhering to the innerwall of the first cup 42 and the peripheral surface and the bottomsurface of the outer periphery 15A and the SPM adhering to the pipe wallof the first common pipe 93 are washed away with the cleaning liquidspouted from the first and second cleaning liquid nozzles 76, 78.

In this exemplary process, the organic solvent supplying step (S5) isperformed after the end of the rinsing step (S4). Thus, the rinse liquidintruding into the minute pattern on the front surface of the substrateW is replaced with the organic solvent (IPA) having a lower surfacetension prior to a spin drying step (S6) to be described later. Thisprevents the collapse of the pattern in the subsequent spin drying step(S6).

After a lapse of a predetermined period from the start of the spoutingof the rinse liquid, the controller 8 controls the spin motor 13 toreduce the rotation speed of the substrate W stepwise from the sulfuricacid-containing liquid treatment speed to a puddling speed (e.g., about10 rpm). After the rotation speed of the substrate W is reduced to thepuddling speed (e.g., about 10 rpm), the controller 8 controls the spinmotor 13 to maintain the rotation speed of the substrate W at thepuddling speed. Thus, the rinse liquid film is retained in a puddle formon the entire upper surface of the substrate W.

After a lapse of a predetermined period from the time at which therotation speed of the substrate W is reduced to the puddling speed(e.g., about 10 rpm), the controller 8 closes the rinse liquid valve 41to stop spouting the rinse liquid from the rinse liquid nozzle 39. Thecontroller 8 closes the first and second cleaning liquid valves 84, 89to stop spouting the cleaning liquid from the first and second cleaningliquid nozzles 76, 78.

Then, the controller 8 starts the organic solvent supplying step (secondchemical liquid supplying step, Step S5). More specifically, thecontroller 8 controls the second arm pivoting unit 36 to move theorganic solvent nozzle 33 from the home position to the treatmentposition. Thus, the organic solvent nozzle 33 is located above thecenter portion of the substrate W. Further, the controller 8 controlsthe guard lift unit 48 to move the fourth guard 47 to the upper position(uppermost position) to bring the fourth guard 47 into opposed relationto the peripheral surface of the substrate W with the first to thirdguards 44 to 46 located at the lower position (lowermost position).Further, the controller 8 controls the first recovery valve 95A and thefirst drain valve 96A to set the destination of the liquid flowingthrough the first common pipe 93 to the first drain pipe 96.

After the organic solvent nozzle 33 is located above the upper surfacecenter portion of the substrate W, the controller 8 opens the organicsolvent valve 38 while maintaining the rotation speed of the substrate Wat the puddling speed. Thus, as shown in FIG. 7C, IPA is spouted fromthe spout of the organic solvent nozzle 33 to be applied to the uppersurface center portion of the substrate W.

The controller 8 opens the organic solvent valve 38 to spout liquid IPAfrom the organic solvent nozzle 33 toward the upper surface centerportion of the substrate W, while maintaining the rotation speed of thesubstrate W at the puddling speed. Thus, IPA is supplied to the uppersurface of the substrate W, whereby the rinse liquid in the liquid filmon the upper surface of the substrate W is sequentially replaced withIPA. Thus, a liquid film of IPA is retained in a puddle form on theupper surface of the substrate W as covering the entire upper surface ofthe substrate W. Even after the liquid film is substantially replacedwith the IPA liquid film on the entire upper surface of the substrate W,the supply of IPA to the upper surface of the substrate W is continued.Therefore, IPA flows out from the periphery of the substrate W.

IPA flowing out from the periphery of the substrate W is received by theinner wall of the fourth guard 47 opposed to the peripheral surface ofthe substrate W. Then, IPA flows down on the inner wall of the fourthguard 47, and is guided by the projection 71 of the third guard 46 to bereceived by the drain channel 75 of the third cup 74 and further guidedto the drain unit (not shown) from the bottom of the third cup 74through the drain pipe (not shown).

In the organic solvent supplying step (S5) in which the substrate W isrotated at the puddling speed, a smaller centrifugal force acts on IPApresent on the peripheral portion of the substrate W and, therefore, IPAdrips from the periphery of the substrate W generally verticallydownward. Therefore, some of IPA flowing out laterally of the substrateW does not flow on the fourth guard 47 but is liable to enter the insideof the innermost first guard 44, as indicated by broken lines in FIG.7C, to adhere to the inner wall of the first cup 42 and the pipe wall ofthe first common pipe 93. If the sulfuric acid-containing liquidsupplying step (S3) for the next substrate treatment (for the nextresist removing process) is started with IPA adhering to (or remainingon) the inner wall of the first cup 42, the outer periphery 15A of thespin base 15 and the pipe wall of the first common pipe 93, there is apossibility that the SPM and IPA are accidentally brought into contactwith each other or mixed together in the sulfuric acid-containing liquidsupplying step (S3).

To cope with this, as shown in FIGS. 3 and 7C, the controller 8 opensthe first cleaning liquid valve 84 and the second cleaning liquid valve89 in the organic solvent supplying step (S5) to spout the cleaningliquid from the first cleaning liquid outlet ports 80 of the firstcleaning liquid nozzles 76 and the second cleaning liquid outlet ports81 of the second cleaning liquid nozzles 78 (second cleaning liquidsupplying step). That is, the second cleaning liquid supplying step isperformed in the organic solvent supplying step (S5).

In the second cleaning liquid supplying step, the cleaning liquidspouted from the first cleaning liquid nozzles 76 is sprayed onto theperipheral surface and the bottom surface of the outer periphery 15A.Further, the cleaning liquid spouted from the second cleaning liquidoutlet ports 81 is sprayed onto the upper inner wall portion of thelower portion 58 of the first guard 44. In the second cleaning liquidsupplying step, the cleaning liquid flows in the same manner as in thefirst cleaning liquid supplying step. Thus, IPA adhering to the innerwall of the first cup 42 and the peripheral surface and the bottomsurface of the outer periphery 15A and IPA adhering to the pipe wall ofthe first common pipe 93 are washed away with the cleaning liquid.

After a lapse of a predetermined puddling period (e.g., about 10seconds) from the start of the spouting of IPA, the controller 8controls the spin motor 13 to accelerate the rotation of the substrate Wfrom the puddling speed to a higher rotation speed (e.g., about 1000rpm) while continuing the spouting of IPA. After the rotation speed ofthe substrate W reaches the higher rotation speed, the controller 8closes the organic solvent valve 38 to stop spouting IPA from theorganic solvent nozzle 33, and closes the first and second cleaningliquid valves 84, 89 to stop spouting the cleaning liquid from the firstand second cleaning liquid nozzles 76, 78.

After the spouting of IPA is stopped, the controller 8 performs the spindrying step (Step S6) with the fourth guard 47 opposed to the peripheralsurface of the substrate W as shown in FIG. 7D. That is, the controller8 maintains the rotation speed of the substrate W at the higher rotationspeed (e.g., about 1000 rpm). Thus, IPA adhering to the substrate W isspun off to dry the substrate W.

Further, the controller 8 opens the first cleaning liquid valve 84 andthe second cleaning liquid valve 89 in the spin drying step (S6) tospout the cleaning liquid from the first cleaning liquid outlet ports 80of the first cleaning liquid nozzles 76 and from the second cleaningliquid outlet ports 81 of the second cleaning liquid nozzles 78 (thirdcleaning liquid supplying step). That is, the third cleaning liquidsupplying step is performed in the spin drying step (S6).

In the third cleaning liquid supplying step, the cleaning liquid spoutedfrom the first cleaning liquid nozzles 76 is sprayed onto the peripheralsurface and the bottom surface of the outer periphery 15A. The cleaningliquid spouted from the second cleaning liquid outlet ports 81 issprayed onto the upper inner wall portion of the lower portion 58 of thefirst guard 44. In the third cleaning liquid supplying step, thecleaning liquid flows in the same manner as in the first cleaning liquidsupplying step. Thus, IPA adhering to the inner wall of the first cup 42and the peripheral surface and the bottom surface of the outer periphery15A and IPA adhering to the pipe wall of the first common pipe 93 arewashed away with the cleaning liquid.

After the spin drying step (S6) is performed for a predetermined period,the controller 8 controls the spin motor 13 to stop the rotation of thespin chuck 3 (the rotation of the substrate W) (Step S7).

Thus, the resist removing process for the single substrate W iscompleted, and the treated substrate W is unloaded from the treatmentchamber 2 by the transport robot (Step S8).

Subsequently, a substrate W to be next treated is loaded into thetreatment chamber 2, and the substrate treatment (resist removingprocess) shown in FIG. 6 is performed again. This substrate treatment isrepeatedly performed until one lot of substrates W (e.g., 25 substratesW) are treated.

In the first embodiment, the sulfuric acid-containing liquid supplyingstep (S3) and the organic solvent supplying step (S5) are performed inthe single treatment chamber. The SPM and IPA are a combination ofchemical liquids which are liable to cause a hazard when beingaccidentally brought into contact with each other or mixed together.More specifically, the accidental mixing of the SPM and IPA may causeexplosion due to the dehydrating action of sulfuric acid contained inthe SPM.

In the first embodiment, as described above, the sulfuricacid-containing liquid supplying step (S3), the rinsing step (S4), theorganic solvent supplying step (S5) and the spin drying step (S6) areperformed in this order in the same treatment chamber. Further, thecleaning liquid is supplied to the inner wall of the first cup 42 andthe peripheral surface and the bottom surface of the outer periphery 15Ain the rinsing step (S4), the organic solvent supplying step (S5) andthe spin drying step (S6).

If the organic solvent supplying step (S5) is started with the SPMadhering to (or remaining on) the inner wall of the first cup 42, theouter periphery 15A of the spin base 15 and the pipe wall of the firstcommon pipe 93, there is a possibility that the SPM and IPA areaccidentally brought into contact with each other or mixed together inthe organic solvent supplying step (S5).

In the first embodiment, the cleaning liquid is supplied to the innerwall of the first cup 42 and the peripheral surface and the bottomsurface of the outer periphery 15A (base wall surface) in the rinsingstep (S4) to be performed after the sulfuric acid-containing liquidsupplying step (S3), whereby the SPM is removed from the inner wall ofthe first cup 42 and the peripheral surface and the bottom surface ofthe outer periphery 15A before the start of the organic solventsupplying step (S5). Therefore, the SPM remains neither on the innerwall of the first cup 42 nor on the peripheral surface and the bottomsurface of the outer periphery 15A at the start of the organic solventsupplying step (S5). This reliably prevents the accidental mixing of theSPM and IPA in the organic solvent supplying step (S5).

If the sulfuric acid-containing liquid supplying step (S3) for the nextsubstrate treatment (resist removing process) is started with IPAadhering to (or remaining on) the inner wall of the first cup 42, theouter periphery 15A of the spin base 15 and the pipe wall of the firstcommon pipe 93, there is a possibility that the SPM and IPA areaccidentally brought into contact with each other or mixed together inthe sulfuric acid-containing liquid supplying step (S3).

In the first embodiment, the cleaning liquid is supplied to the innerwall of the first cup 42 and the peripheral surface and the bottomsurface of the outer periphery 15A in the organic solvent supplying step(S5), whereby IPA is removed from the inner wall of the first cup 42 andthe peripheral surface and the bottom surface of the outer periphery 15Ain the organic solvent supplying step (S5). After the end of the organicsolvent supplying step (S5), therefore, IPA remains neither on the innerwall of the first cup 42 nor on the peripheral surface and the bottomsurface of the outer periphery 15A. This reliably prevents theaccidental mixing of the SPM and IPA in the sulfuric acid-containingliquid supplying step (S3) for the next substrate treatment. Further,the cleaning liquid is supplied to the inner wall of the first cup 42and the peripheral surface and the bottom surface of the outer periphery15A in the spin drying step (S6), whereby IPA is removed from the innerwall of the first cup 42 and the peripheral surface and the bottomsurface of the outer periphery 15A in the spin drying step (S6). Afterthe end of the spin drying step (S6), therefore, IPA remains neither onthe inner wall of the first cup 42 nor on the peripheral surface and thebottom surface of the outer periphery 15A. This reliably prevents theaccidental mixing of the SPM and IPA in the sulfuric acid-containingliquid supplying step (S3) for the next substrate treatment.

As described above, even if the plural types of chemical liquids to beused in combination for the substrate treatment (e.g., SPM and IPA) areliable to cause a hazard when being accidentally brought into contactwith each other or mixed together, the substrate treatment apparatus 1is capable of completing the substrate treatment in the single treatmentchamber 2 while reliably preventing the accidental mixing of thechemical liquids (SPM and IPA).

Further, the destination of the liquid flowing through the first commonpipe 93 is set to the first drain pipe 96 when the cleaning liquid issupplied to the inner wall of the first cup 42 and the peripheralsurface and the bottom surface of the outer periphery 15A. Therefore,the cleaning liquid supplied to the inner wall of the first cup 42 andthe peripheral surface and the bottom surface of the outer periphery 15Ais guided to the first common pipe 93 through the first drain/recoveryport 92 provided in the bottom of the first cup 42, and then to thefirst drain pipe 96. Therefore, even if the SPM or IPA adheres to thepipe wall of the first common pipe 93 in the sulfuric acid-containingliquid supplying step (S3) or the organic solvent supplying step (S5),the adhering SPM or IPA can be washed away with the cleaning liquidflowing through the first common pipe 93. This reliably prevents theaccidental mixing of the SPM and IPA on the pipe wall of the firstcommon pipe 93.

The first cleaning liquid nozzles 76 are disposed obliquely below theouter periphery 15A. If the first cleaning liquid nozzles 76 weredisposed laterally of the outer periphery 15A of the spin base 15, thefirst cleaning liquid nozzles 76 would be located between the spin baseand the cup as seen in plan, resulting in size increase of the substratetreatment apparatus 1. In this embodiment, in contrast, the firstcleaning liquid nozzles 76 are not located laterally of the outerperiphery 15A of the spin base 15, so that the size of the substratetreatment apparatus 1 is not increased. Thus, the substrate treatmentapparatus 1 is capable of supplying the cleaning liquid to theperipheral surface of the outer periphery 15A of the spin base 15without the size increase thereof. In addition, the cleaning liquid issupplied to the outer periphery 15A obliquely from below, whereby theSPM or IPA can be advantageously removed from the bottom surface of theouter periphery 15A of the spin base 15.

Since the second cleaning liquid nozzles 78 are absent in the regionnear the first drain/recovery port 92, the cleaning liquid spouted fromthe second cleaning liquid nozzles 78 to be supplied to the first cup 42moves circumferentially of the first cup 42 toward the firstdrain/recovery port 92 in the first cup 42 to be guided to the firstcommon pipe 93 from the first drain/recovery port 92. That is, adistance for which the cleaning liquid moves in the first cup 42 isincreased. Thus, the SPM or IPA can be efficiently removed from thefirst cup 42.

FIG. 8 is a diagram of a substrate treatment apparatus 201 according toa second embodiment of the present invention as seen in a horizontaldirection. FIG. 9 is a diagram showing the inside of a treatment chamber202 taken along a sectional plane IX-IX in FIG. 8. FIG. 10 is asectional view showing the inside of the treatment chamber 202 takenalong a sectional plane X-X in FIG. 8.

The substrate treatment apparatus 201 is of a single substrate treatmenttype adapted to treat a front surface (having a device formation region)of a substrate W (e.g., a round semiconductor wafer or the like) with aliquid for a cleaning process or an etching process. The substratetreatment apparatus 201 includes a box-shaped treatment chamber 202having an inside space, a spin chuck (substrate holding mechanism) 203which horizontally holds a single substrate W in the treatment chamber202 and rotates the substrate W about a vertical rotation axis A1extending through the center of the substrate W, a sulfuricacid-containing liquid supplying unit 204 which supplies an SPM as anexemplary sulfuric acid-containing liquid (first chemical liquid) to thesubstrate W held by the spin chuck 203, an organic solvent supplyingunit 205 which supplies IPA as an exemplary organic solvent (an organicsolvent having a lower surface tension, second chemical liquid) to thefront surface (upper surface) of the substrate W held by the spin chuck203, a rinse liquid supplying unit 206 which supplies a rinse liquid tothe front surface (upper surface) of the substrate W held by the spinchuck 203, a tubular treatment cup 207 surrounding the spin chuck 203, acontroller 208 which controls the operations of devices provided in thesubstrate treatment apparatus 201 and the opening and closing of valves,and a vat 209 provided on the bottom of the treatment chamber 202.

The treatment chamber 202 includes a boxed-shaped partition wall 210 tobe opened and closed by a shutter 211 (see FIG. 9), an FFU 212 servingas an air supplying unit which supplies clean air into the inside of thepartition wall 210 (into the treatment chamber 2) from above thepartition wall 210, and an evacuation device (not shown) which expelsgas from the treatment chamber 202 from a lower portion of the partitionwall 210. As shown in FIGS. 9 and 10, the treatment chamber 202 has abox shape having a generally rectangular plan shape (with one of thecorners of the rectangle being obliquely beveled). The partition wall210 includes a top wall 213 extending horizontally (X), and five sidewalls 215. The shutter 211 is provided in association with an opening(not shown) formed in one of the side walls 215.

The FFU 212 is disposed above the top wall 213, and attached to a topportion of the top wall 213. The FFU 212 supplies the clean air into thetreatment chamber 202 from the top portion of the partition wall 210.The evacuation device is connected to a bottom portion of the treatmentcup 207 through a cup evacuation duct 349, and the inside of thetreatment cup 207 is evacuated through the bottom portion of thetreatment cup 207. The FFU 212 and the evacuation device forma down flowin the treatment chamber 202.

A chuck of a clamping type adapted to horizontally clamp the substrate Wto horizontally hold the substrate W is used as the spin chuck 203. Morespecifically, the spin chuck 203 includes a spin motor 216, a spin shaft217 unified with a drive shaft of the spin motor 216, and a disk-shapedspin base 218 horizontally attached to an upper end of the spin shaft217.

The spin shaft 217 is a vertical hollow shaft, in which a lower surfacesupply line (not shown) is inserted. A treatment liquid (e.g., achemical liquid or pure water (DIW)) is supplied to the lower surfacesupply line. Further, a lower surface nozzle 219 which spouts thetreatment liquid supplied to the lower surface supply line is providedat an upper end of the lower surface supply line. The lower surfacenozzle 219 spouts the treatment liquid generally vertically upward, andthe treatment liquid spouted from the lower surface nozzle 219 isapplied generally perpendicularly to a center portion of a lower surfaceof the substrate W held by the spin chuck 203.

A plurality of clamping members 220 (three or more clamping members,e.g., six clamping members) are circumferentially provided on an uppersurface of the spin base 218. The clamping members 220 are disposed incircumferentially properly spaced relation according to the outerperipheral shape of the substrate W on a peripheral portion of the uppersurface of the spin base 218.

As shown in FIG. 8, the sulfuric acid-containing liquid supplying unit204 includes a sulfuric acid-containing liquid nozzle (first chemicalliquid nozzle) 221 which spouts the SPM toward the front surface of thesubstrate W, a third nozzle arm 222 having a distal end to which thesulfuric acid-containing liquid nozzle 221 is attached, a third pivotshaft 223 extending vertically on a lateral side of the spin chuck 203and pivotally supporting the third nozzle arm 222, and a third armpivoting unit (first moving mechanism) 224 which rotates the third pivotshaft 223 to move the third nozzle arm 222 to thereby move the sulfuricacid-containing liquid nozzle 221. The sulfuric acid-containing liquidnozzle 221 is, for example, a straight nozzle which spouts the SPM inthe form of continuous stream, and is attached to the horizontal thirdnozzle arm 222, for example, with its spout directed downward. The thirdnozzle arm 222 extends horizontally.

The sulfuric acid-containing liquid supplying unit 204 further includesa sulfuric acid-containing liquid line 225 through which the SPM isguided to the sulfuric acid-containing liquid nozzle 221, and a sulfuricacid-containing liquid valve 226 which opens and closes the sulfuricacid-containing liquid line 225. With the sulfuric acid-containingliquid valve 226 open, the SPM is supplied from an SPM supply source tothe sulfuric acid-containing liquid nozzle 221 through the sulfuricacid-containing liquid line 225. Thus, the SPM is spouted from thesulfuric acid-containing liquid nozzle 221.

The sulfuric acid-containing liquid line 225 is branched at a branchposition 225A between the sulfuric acid-containing liquid nozzle 221 andthe sulfuric acid-containing liquid valve 226, and one end of a firstsuction line 227 for sucking the SPM from the inside of the sulfuricacid-containing liquid line 225 is connected to the sulfuricacid-containing liquid line 225 at the branch position 225A. A firstsuction valve 228 is provided in the first suction line 227, and theother end of the first suction line 227 is connected to a first suctiondevice (not shown). For example, the first suction device is constantlydriven. When the first suction valve 228 is opened, an inside portion ofthe sulfuric acid-containing liquid line 225 downstream of the firstbranch position 225A is evacuated, so that the SPM is sucked from thedownstream inside portion.

The third arm pivoting unit 224 pivots the third nozzle arm 222 aboutthe third pivot shaft 223, whereby the sulfuric acid-containing liquidnozzle 221 is horizontally moved along an arcuate path. The third armpivoting unit 224 horizontally moves the sulfuric acid-containing liquidnozzle 221 between a treatment position such that the SPM spouted fromthe sulfuric acid-containing liquid nozzle 221 is applied to the uppersurface of the substrate W and a first home position 229 at which thesulfuric acid-containing liquid nozzle 221 is located adjacent the spinchuck 203 as seen in plan. Further, the third arm pivoting unit 224horizontally moves the sulfuric acid-containing liquid nozzle 221between a center position such that the SPM spouted from the sulfuricacid-containing liquid nozzle 221 is applied to the upper surface centerportion of the substrate W and a peripheral position such that the SPMspouted from the sulfuric acid-containing liquid nozzle 221 is appliedto the upper surface peripheral portion of the substrate W. The centerposition and the peripheral position are each defined as the treatmentposition. The sulfuric acid-containing liquid nozzle 221 may be a fixednozzle which is fixedly disposed with its spout directed toward apredetermined position (e.g., center portion) on the upper surface ofthe substrate W.

The organic solvent supplying unit 205 includes an organic solventnozzle (second chemical liquid nozzle) 233 which spouts IPA toward thefront surface of the substrate W, a fourth nozzle arm 234 having adistal end to which the organic solvent nozzle 233 is attached, a fourthpivot shaft 235 extending vertically on a lateral side of the spin chuck203 and pivotally supporting the fourth nozzle arm 234, and a fourth armpivoting unit (second moving mechanism) 236 which rotates the fourthpivot shaft 235 to move the second nozzle arm 234 to thereby move theorganic solvent nozzle 233. The organic solvent nozzle 233 is, forexample, a straight nozzle which spouts IPA in the form of continuousstream, and is attached to the horizontal fourth nozzle arm 234, forexample, with its spout directed downward. The fourth nozzle arm 234extends horizontally.

The organic solvent supplying unit 205 further includes an organicsolvent line 237 through which IPA is guided to the organic solventnozzle 233, and an organic solvent valve 238 which opens and closes theorganic solvent line 237. With the organic solvent valve 238 open, IPAis supplied from an IPA supply source to the organic solvent nozzle 233through the organic solvent line 237. Thus, IPA is spouted from theorganic solvent nozzle 233.

The organic solvent line 237 is branched at a branch position 237Abetween the organic solvent nozzle 233 and the organic solvent valve238, and one end of a second suction line (suction mechanism) 239 forsucking IPA from the inside of the organic solvent line 237 and theinside of the organic solvent nozzle 233 is connected to the organicsolvent line 237 at the branch position 237A. A second suction valve 240(suction mechanism) is provided in the second suction line 239, and theother end of the second suction line 239 is connected to a secondsuction device (not shown). For example, the second suction device isconstantly driven. When the second suction valve 240 is opened, aninside portion of the organic solvent line 237 downstream of the secondbranch position 237A is evacuated, so that IPA is sucked from thedownstream inside portion. The second suction device may be providedseparately from the first suction device, or the first suction devicemay double as the second suction device.

The fourth arm pivoting unit 236 pivots the fourth nozzle arm 234 aboutthe fourth pivot shaft 235, whereby the organic solvent nozzle 233 ishorizontally moved along an arcuate path. The fourth arm pivoting unit236 horizontally moves the organic solvent nozzle 233 between atreatment position such that IPA spouted from the organic solvent nozzle233 is applied to the upper surface of the substrate W and a second homeposition 241 at which the organic solvent nozzle 233 is located adjacentthe spin chuck 203. Further, the fourth arm pivoting unit 236horizontally moves the organic solvent nozzle 233 between a centerposition such that IPA spouted from the organic solvent nozzle 233 isapplied to the upper surface center portion of the substrate W and aperipheral position such that IPA spouted from the organic solventnozzle 233 is applied to the upper surface peripheral portion of thesubstrate W. The center position and the peripheral position are eachdefined as the treatment position. The organic solvent nozzle 233 may bea fixed nozzle which is fixedly disposed with its spout directed towarda predetermined position (e.g., center portion) on the upper surface ofthe substrate W.

The rinse liquid supplying unit 206 includes a rinse liquid nozzle 230which spouts the rinse liquid toward the substrate W held by the spinchuck 203, a rinse liquid line 231 which supplies the rinse liquid tothe rinse liquid nozzle 230, and a rinse liquid valve 232 which switcheson and off the supply of the rinse liquid from the rinse liquid line 231to the rinse liquid nozzle 230. The rinse liquid nozzle 230 is a fixednozzle which spouts the rinse liquid with its spout kept still. Therinse liquid supplying unit 206 may include a rinse liquid nozzle movingdevice which moves the rinse liquid nozzle 230 to move the rinse liquidapplication position on the upper surface of the substrate W.

With the rinse liquid valve 232 open, the rinse liquid supplied from therinse liquid line 231 to the rinse liquid nozzle 230 is spouted from therinse liquid nozzle 230 toward the upper surface center portion of thesubstrate W.

The treatment cup 207 includes a tubular wall 250 having, for example, acylindrical shape and surrounding the spin chuck 203, a plurality ofcups 242, 243, 244 (fourth, fifth and sixth cups 242, 243, 244) providedbetween the spin chuck 203 and the tubular wall 250, a plurality ofguards 246 to 249 (fifth to eighth guards 246 to 249) which each receivea treatment liquid (chemical liquid and rinse liquid) scattered aroundthe substrate W, and a guard lift mechanism (not shown) which includes,for example, a ball screw mechanism for independently moving up and downthe respective guards 246 to 249. By driving the guard lift mechanism,the guards 246 to 249 are independently moved up and down.

As shown in FIG. 8, the cups 242 to 244 each have a cylindrical shape,and surround the spin chuck 203 between the spin chuck 203 and thetubular wall 250. The fifth cup 243 located at the second innermostposition is disposed outward of the fourth cup 242. The sixth cup 244located at the third innermost position is disposed outward of the fifthcup 243. The sixth cup 244 is, for example, unitary with the six guard247, and moved up and down together with the sixth guard 247. The cups242 to 244 each define an annular channel which opens upward. Thetreatment liquid guided into the cup 242 to 244 is sent to a recoveryunit or a drain unit (not shown) through the channel. Thus, thetreatment liquid used for the treatment of the substrate W is recoveredor drained.

As shown in FIG. 8, the guards 246 to 249 each have a cylindrical shape,and surround the spin chuck 203 between the spin chuck 203 and thetubular wall 250. The guards 246 to 249 each include an annular inclinedportion 251 extending obliquely upward toward the rotation axis A1, anda cylindrical guide portion 252 extending downward from a lower edge ofthe inclined portion 251. An upper edge of the inclined portion 251defines an inner periphery of the guard 246 to 249, and has a greaterdiameter than the substrate W and the spin base 218. The four inclinedportions 251 are vertically stacked one on another. The four guideportions 252 are coaxial with each other. The guide portions 252 of thethree inner guards 246 to 248 can be moved into and out of the threecups 242 to 244, respectively. That is, the treatment cup 207 iscollapsible, and the guard lift mechanism moves up and down at least oneof the four guards 246 to 249, whereby the treatment cup 207 is expandedor collapsed.

The seventh guard 248 out of the three inner guards 246 to 248 includesa suspended portion 248 a extending vertically downward from an outerperipheral edge of the inclined portion 251 thereof, and a projection248 b projecting radially outward from a lower edge of the suspendedportion 248 a. The projection 248 b has an annular drain channel 245which opens upward. The drain channel 245 is located below the guideportion of the eighth guard 249. Liquid received by the drain channel245 is guided to the drain unit (not shown).

The guard lift mechanism moves up and down the respective guards 246 to249 between an upper position such that the guard upper edge is locatedabove the substrate W and a lower position such that the guard upperedge is located below the substrate W. The guard lift mechanism canretain each of the guards 246 to 249 at a desired position between theupper position and the lower position. When the treatment liquid issupplied to the substrate W or when the substrate W is dried, any one ofthe guards 246 to 249 is opposed to the peripheral surface of thesubstrate W. Where the inner sixth guard 247 is opposed to theperipheral surface of the substrate W, for example, the fifth guard 246is located at the lower position, and the sixth guard 247, the seventhguard 248 and the eighth guard 249 are located at the upper position.Where the seventh guard 248 is opposed to the peripheral surface of thesubstrate W, the seventh guard 248 and the eighth guard 249 are locatedat the upper position, and the fifth guard 246 and the sixth guard 247are located at the lower position.

The tubular wall 250 has a cylindrical shape (in FIGS. 9 and 10, thetubular wall 250 is illustrated as having an oval shape for easierdescription (the same applies to FIGS. 17 and 18)). As shown in FIG. 10,the tubular wall 250 has first and second communication holes 253, 254provided in two circumferential portions of a lower edge portion thereofas extending therethrough. The first communication hole 253 permitscommunication between an inner space IS and a first outer space OS1 tobe described later, and the second communication hole 254 permitscommunication between the inner space IS and a second outer space OS2 tobe described later. An upstream end of the cup evacuation duct 349 isconnected to a predetermined circumferential portion of the lower edgeportion of the tubular wall 250. A downstream end of the cup evacuationduct 349 is connected to the evacuation device (not shown) providedoutside the apparatus. The internal atmosphere of the tubular wall 250is expelled through the cup evacuation duct 349 by the evacuationdevice.

The tubular wall 250 partitions the inside space of the treatmentchamber 202 into the inner space IS defined inward of the tubular wall250 as seen in plan and an outer space OS defined outward of the tubularwall 250 as seen in plan. In other words, the inside space of thetreatment chamber 202 includes the inner space IS and the outer spaceOS.

As shown in FIG. 8, a cover 255 is disposed at substantially the samelevel as an upper edge of the tubular wall 250 around the tubular wall250. The cover 255 partitions the outer space OS into an upper outerspace OSU and a lower outer space OSD. The third and fourth pivot shafts223, 235 and the first and second home positions 229, 241 are located inthe upper outer space OSU. The cover 255 includes, for example, aplurality of plate segments 256. The plate segments 256 are fixed to thetubular wall 250 and the side walls 215 by bolts (not shown). The platesegments 256 are disposed in circumferentially spaced relation. Theupper outer space OSU communicates with the lower outer space OSDthrough gaps each defined between two circumferentially adjacent platesegments 256, gaps defined between the tubular wall 250 and the platesegments 256 and gaps defined between the side walls 215 and the platesegments 256. In FIG. 9, the cover 255 and the plate segments 256 arenot shown (the same applies to FIG. 17).

As shown in FIGS. 9 and 10, two partition walls 257 are provided betweenthe tubular wall 250 and the side walls 215 at least in the bottomportion as radially extending from the tubular wall 250. The partitionwalls 257 are each postured vertically. The two partition walls 257circumferentially partitions the outer space OS into the first outerspace OS1 and the second outer space OS2. Upper edges of the partitionwalls 257 horizontally extend at a height level slightly lower than theupper edge of the tubular wall 250. Thus, the first outer space OS1 andthe second outer space OS2 are isolated from each other in a lowerportion (including the bottom portion) of the treatment chamber 202.

The first outer space OS1 is a relatively large space including threecorners of the treatment chamber 202 as seen in plan. The first homeposition 229 is defined in the first outer space OS1. The third andfourth pivot axes 223, 235 (see FIG. 9) are disposed in the first outerspace OS1. On the other hand, the second outer space OS2 is a relativelysmall space including a space opposed to the shutter 211. The secondhome position 241 is defined in the second outer space OS2.

The vat 209 is disposed on the entire bottom of the treatment chamber202 so as to prevent the chemical liquid (SPM and IPA) used in thetreatment chamber 202 from flowing out of the treatment chamber 202. Thevat 209 includes an inner vat 260 disposed on the bottom of the innerspace IS defined inward of the tubular wall 250, a first outer vat 261disposed on the bottom of the first outer space OS1, and a second outervat 262 disposed on the bottom of the second outer space OS2.

The first outer vat 261 serves as a vat (first vat) for receiving theSPM, and the inner vat 260 and the second outer vat 262 each serve as avat (second vat) for receiving IPA. In other words, the second vatextends over the bottom of the second outer space OS2 and the bottom ofthe inner space IS. In FIG. 10, the vats which receive different liquidsare hatched differently for easy understanding (the same applies to FIG.18).

FIG. 11 is a sectional view of the first outer vat 261 taken along asectional plane XI-XI in FIG. 10. FIG. 12 is a sectional view takenalong a sectional plane XII-XII in FIG. 11.

As shown in FIG. 10, the first outer vat 261 is dimensioned andconfigured in conformity with the bottom of the first outer space OS1,and covers the entire bottom of the first outer space OS1 from below.The first outer vat 261 is a plate made of a chemical-resistant material(e.g., PVC). The entire periphery of the first outer vat 261 is weldedto be connected to lower edges of the partition walls 257, the tubularwall 250 and the side walls 215 (see FIG. 8) for prevention of liquidleakage from the first outer space OS1.

The first outer vat 261 has a first reception surface 263. The firstreception surface 263 is defined on the upper surface of the first outervat 261 for receiving the SPM dripping from above. The first receptionsurface 263 has a first lowermost portion 264. A most portion of thefirst reception surface 263 excluding the first lowermost portion 264 isinclined downward toward the first lowermost portion 264 with respect tohorizontal directions X. Therefore, the SPM received on differentportions of the first reception surface 263 flows toward the firstlowermost portion 264 due to height differences from the first lowermostportion 264.

As shown in FIG. 10, the second outer vat 262 is dimensioned andconfigured in conformity with the bottom of the second outer space OS2,and covers the entire bottom of the second outer space OS2 from below.The second outer vat 262 is, for example, a single plate made of achemical-resistant material (e.g., PVC). The entire periphery of thesecond outer vat 262 is welded to be connected to the lower edges of thepartition walls 257, the tubular wall 250 and the side walls 215 (seeFIG. 8) for prevention of liquid leakage from the second outer spaceOS2.

The second outer vat 262 has a second reception surface 265 defined onan upper surface thereof for receiving IPA dripping from above. Thesecond receiving surface 265 has a second lowermost portion 266. A mostportion of the second reception surface 265 excluding the secondlowermost portion 266 is inclined downward toward the second lowermostportion 266 with respect to the horizontal directions X. Therefore, IPAreceived on different portions of the second reception surface 265 flowstoward the second lowermost portion 266 due to height differences fromthe second lowermost portion 266.

As shown in FIG. 10, the inner vat 260 is a single plate made of achemical-resistant material (e.g., PVC). The inner vat 260 isdimensioned and configured in conformity with the bottom of the innerspace IS defined inward of the tubular wall 250. The inner vat 260covers the entire bottom of the inner space IS from below. That is, theinner vat 260 defines the bottom of the tubular wall 250. In otherwords, the inner vat 260 defines a part of the bottom wall of thetreatment chamber 202. The entire periphery of the inner vat 260 iswelded to be connected to the lower edge of the tubular wall 250 forprevention of liquid leakage from the inner space IS.

As shown in FIGS. 8 and 10, the inner vat 260 has first and second drainports 267, 268 provided in an outer peripheral portion of an innerreception surface 271 thereof. The first drain port 267 and the seconddrain port 268 are disposed in circumferentially spaced relation (in thesecond embodiment, the first drain port 267 and the second drain port268 are disposed on opposite sides of the rotation axis A1). A firstdrain pipe 269 is connected to the first drain port 267. A downstreamend portion of the first drain pipe 269 extends to a first drain unit(not shown).

The inner reception surface 271 is defined on an upper surface of theinner vat 260 for receiving IPA dripping from above. The inner receptionsurface 271 is inclined. The second drain port 268 is provided in alowermost portion of the inner reception surface 271. In the secondembodiment, the lowermost portion of the inner reception surface 271 isdefined at a predetermined position in an outer peripheral portion ofthe inner vat 260. A portion of the inner reception surface 271excluding the lowermost portion is inclined downward toward the seconddrain port 268 with respect to the horizontal directions X. A seconddrainpipe 270 is connected to the second drain port 268. A downstreamend portion of the second drain pipe 270 extends to a second drain unit(not shown) different from the first drain unit.

As described above, the inner space IS and the first outer space OS1 areisolated from each other in the bottom portion of the treatment chamber202. Therefore, there is no liquid communication between the inner vat260 disposed in the bottom of the inner space IS and the first outer vat261 disposed in the bottom of the first outer space OS1. Further, thefirst outer space OS1 and the second outer space OS2 are isolated fromeach other in the bottom portion of the treatment chamber 202 asdescribed above, so that there is no liquid communication between thefirst outer vat 261 disposed in the bottom of the first outer space OS1and the second outer vat 262 disposed in the bottom of the second outerspace OS2.

As shown in FIGS. 10 and 12, the first drain port 267 is connected tothe first lowermost portion 264 of the first reception surface 263through a first tube 273. The SPM flowing on the first reception surface263 to reach the first lowermost portion 264 is guided to the firstdrain port 267 through the first tube 273. That is, the first tube 273is provided as a bypass through which the first lowermost portion 264and the first drain port 267 are connected to each other, so that theSPM present on the first reception surface 263 can be guided to thefirst drain port 267 while being prevented from flowing on the innerreception surface 271 of the inner vat 260. A chemical-resistantmaterial such as a fluororesin is used as a material for the first tube273.

A proximal end of the first tube 273 is connected to the first lowermostportion 264 (i.e., a portion of the tubular wall 250 opposed to thefirst lowermost portion 264) via a first pipe joint 320. The first pipejoint 320 includes a joint body 321 extending through a portion of thetubular wall 250 opposed to the first lowermost portion 264, and a tubeside joint 322 fixed to the proximal end of the first tube 273. Thejoint body 321 is fixed to the tubular wall 250 to close the firstcommunication hole 253 of the tubular wall 250. The joint body 321 hasan inlet port 274, and an insertion hole 323 communicating with theinlet port 274. The joint body 321 is attached to the tubular wall 250with the inlet port 274 directed outward of the tubular wall 250 andwith the insertion hole 323 directed inward of the tubular wall 250.That is, the inlet port 274 is opposed to the first lowermost portion264.

The tube side joint 322 is inserted (screwed) into the insertion hole323 to be thereby locked in the insertion hole 323. In this lockedstate, the inside of the first tube 273 communicates with the inlet port274. The first lowermost portion 264 and the inner vat 260 are isolatedfrom each other by the join body 321 attached to the tubular wall 250.This eliminates a possibility that the SPM present on the firstlowermost portion 264 enters the inner vat 260 (see FIG. 10).

A distal end of the first tube 273 is connected to the first drain port267 (i.e., an upstream end of the first drain pipe 269) via a secondpipe joint 275.

FIG. 13 is a diagram schematically showing connection between the firsttube 273 and the first drain pipe 269.

The second pipe joint 275 includes a joint body 276 attached to thefirst drain port 267, a tube side joint 277, and a drain side joint 278.The joint body 276 has a flange 279 fixed to the inner vat 260 by aplurality of bolts 280. The joint body 276 includes a first insertionhole 281 in which a distal end of the tube side joint 277 is insertable,a second insertion hole 282 in which the drain side joint 278 isinsertable, and a connection hole 283 through which the first and secondinsertion holes 281, 282 communicate with each other. The tube sidejoint 277 and the drain side joint 278 are respectively inserted(screwed) into the first and second insertion holes 281, 282 to bethereby locked in the first and second insertion holes 281, 282. In thisstate, the inside of the first tube 273 and the inside of the firstdrain pipe 269 communicate with each other. The first drain port 267 andthe inner vat 260 are isolated from each other by the joint body 276attached to the first drain port 267. This eliminates a possibility thatIPA flowing on the inner vat 260 enters the first drain port 267 (firstdrain pipe 269).

The SPM received on different portions of the first reception surface263 of the first outer vat 261 flows toward the first lowermost portion264 due to height differences on the first reception surface 263. TheSPM reaching the first lowermost portion 264 flows into the first tube273 through the first pipe joint 320 to flow through the first tube 273due to a height difference, thereby moving into the first drain pipe 269via the second pipe joint 275 and the first drain port 267. The SPMmoving into the first drain pipe 269 is sent to the first drain unit(not shown) to be drained.

As shown in FIG. 10, the second communication hole 254 is provided in aportion of the tubular wall 250 opposed to the second lowermost portion266 of the second reception surface 265. IPA received on differentportions of the second reception surface 265 of the second vat 209 flowstoward the second lowermost portion 266 due to height differences on thesecond reception surface 265. IPA reaching the second lowermost portion266 moves to the inner reception surface 271 of the inner vat 260 viathe second communication hole 254, and then flows toward the seconddrain port 268 on the inner reception surface 271 due to the heightdifferences on the inner reception surface 271.

IPA flowing onto the inner reception surface 271 of the inner vat 260further flows toward the second drain port 268 due to the heightdifferences on the inner reception surface 271. IPA reaching the seconddrain port 268 is sent to the second drain unit (not shown) through thesecond drainpipe 270 to be drained.

With the aforementioned arrangement, the drain port 267 can be providedin the center portion, thereby simplifying the construction of theapparatus. However, the drain port 267 may be provided in the lowermostportion 264 of the first reception surface 263. In this case, the pipingarrangement can be simplified.

FIG. 14 is a process diagram for explaining another exemplary resistremoving process to be performed on the substrate W by the substratetreatment apparatus 201. FIGS. 15 and 16 are schematic diagrams showingthe exemplary resist removing process.

Referring to FIGS. 8, 9 and 14, the exemplary resist removing processwill be described. Reference will be made to FIGS. 10 to 12 and FIGS. 15and 16 as required.

During the treatment of the substrate W, the inside of the tubular wall250 is forcibly evacuated by driving the evacuation device (not shown).Further, the clean air is supplied into the treatment chamber 202 fromthe FFU 212. Therefore, a down flow of the clean air flowing downward isformed in the treatment chamber 202.

When the resist removing process is to be performed by the substratetreatment apparatus 201, the shutter 211 is opened, and a substrate Wsubjected to a high-dose ion implantation process is loaded into thetreatment chamber 202 by a transport robot (not shown) (Step T1). Thesubstrate W to be loaded is not subjected to a resist ashing process.The substrate W has a front surface formed with a minute pattern havinga higher aspect ratio. More specifically, the controller 208 retractsall the nozzles and the like from above the spin chuck 203, and movesdown the fifth to eighth guards 246 to 249 to the lower position(lowermost position). While the upper edges of the fifth to eighthguards 246 to 249 are located below the substrate holding position atwhich the substrate W is to be held by the spin chuck 203, hands (notshown) of the substrate transport robot (not shown) are moved into thetreatment chamber 202 with the substrate W held thereon, whereby thesubstrate W is transferred to the spin chuck 203 with its front surfacefacing up.

Thereafter, the controller 208 controls the guard lift unit (not shown)to move all the fifth to eighth guards 246 to 249 to the upper position(the uppermost position) with the fifth guard 246 opposed to theperipheral surface of the substrate W.

The controller 208 causes the spin motor 216 to start rotating thesubstrate W (Step T2). The rotation speed of the substrate W isincreased to a predetermined liquid treatment speed (100 to 500 rpm,e.g., about 300 rpm) and maintained at the liquid treatment speed.

After the rotation speed of the substrate W reaches the liquid treatmentspeed, the controller 208 performs a sulfuric acid-containing liquidsupplying step of supplying the SPM to the substrate W (Step T3). Morespecifically, the controller 208 controls the third arm pivoting unit224 to move the sulfuric acid-containing liquid nozzle 221 from thefirst home position 229 defined in the first outer space OS1 to thetreatment position defined in the inner space IS as shown in FIG. 15.

At the first home position 229, the sulfuric acid-containing liquidnozzle 221 is located above a pod (not shown). Before the movement ofthe sulfuric acid-containing liquid nozzle 221 from the first homeposition 229 is started, a part of the SPM changed (in temperature or inquality) with time after the last spouting is often preliminarilydispensed from the sulfuric acid-containing liquid nozzle 221 at thefirst home position 229. For the preliminary dispensing, the controller208 opens the first suction valve 228 after stopping the spouting of theSPM from the sulfuric acid-containing liquid nozzle 221 at the firsthome position 229. Thus, the SPM present in the portion of the sulfuricacid-containing liquid line 225 downstream of the first branch position225A is sucked. The suction of the SPM is continued until a front of theSPM is retracted to a predetermined standby position in the sulfuricacid-containing liquid line 225. After the suction of the SPM, thecontroller starts moving the sulfuric acid-containing liquid nozzle 221to the treatment position. The SPM has a relatively high viscosity and,therefore, hardly drips from the sulfuric acid-containing liquid nozzle221 during the movement from the first home position 229 to thetreatment position. In addition, the inside of the sulfuricacid-containing liquid line 225 is sucked before the start of themovement of the sulfuric acid-containing liquid nozzle 221, so that theSPM is reliably prevented from dripping from the sulfuricacid-containing liquid nozzle 221 during the movement toward thetreatment position.

With the sulfuric acid-containing liquid nozzle 221 located above thesubstrate W, the controller 208 opens the sulfuric acid-containingliquid valve 226 to spout the SPM from the sulfuric acid-containingliquid nozzle 221. In this state, the controller 208 controls the thirdarm pivoting unit 224 to move the SPM application position between thecenter portion and the peripheral portion on the upper surface of thesubstrate W. Thus, the SPM is supplied to the entire upper surface ofthe substrate W, whereby the resist is removed from the substrate W bythe SPM through a chemical reaction between the resist and the SPM. TheSPM supplied onto the upper surface of the substrate W is scattered fromthe periphery of the substrate W laterally of the substrate W, and thenreceived by the inner wall of the fifth guard 246 and guided into thefourth cup 242 to be recovered or drained through the bottom of thefourth cup 242.

After a lapse of a predetermined period from the start of the spoutingof the SPM, the controller 208 closes the sulfuric acid-containingliquid valve 226 to stop spouting the SPM. After the spouting of the SPMfrom the sulfuric acid-containing liquid nozzle 221 is stopped, thecontroller 208 opens the first suction valve 228. Thus, the SPM issucked from the portion of the sulfuric acid-containing liquid line 225downstream of the first branch position 225A. The suction of the SPM iscontinued until the front of the SPM is retracted to the predeterminedstandby position in the sulfuric acid-containing liquid line 225.

After the suction of the SPM, the controller 208 controls the third armpivoting unit 224 to move the sulfuric acid-containing liquid nozzle 221from the treatment position defined in the inner space IS to the firsthome position 229 defined in the first outer space OS1. The SPM has arelatively high viscosity and, therefore, hardly drips from the sulfuricacid-containing liquid nozzle 221 during the movement of the sulfuricacid-containing liquid nozzle 221 from the first home position 229 tothe treatment position. In addition, the inside of the sulfuricacid-containing liquid line 225 is sucked before the start of themovement of the sulfuric acid-containing liquid nozzle 221, so that theSPM is reliably prevented from dripping from the sulfuricacid-containing liquid nozzle 221 during the movement of the sulfuricacid-containing liquid nozzle 221 toward the first home position 229.

After the end of the sulfuric acid-containing liquid supplying step(T3), a rinsing step of supplying the rinse liquid to the substrate W(Step T4) is performed with the fifth guard 246 opposed to theperipheral surface of the substrate W. More specifically, the controller208 opens the rinse liquid valve 232 to spout the rinse liquid from therinse liquid nozzle 230 toward the upper surface center portion of thesubstrate W. The rinse liquid applied to the upper surface centerportion of the substrate W receives a centrifugal force generated by therotation of the substrate W to flow toward the periphery of thesubstrate on the upper surface of the substrate W. Thus, the SPM isrinsed away from the entire upper surface of the substrate W. The rinseliquid supplied to the upper surface of the substrate W is scatteredfrom the periphery of the substrate W laterally of the substrate W, andthen received by the inner wall of the fifth guard 246 and guided intothe fourth cup 242 to be drained through the bottom of the fourth cup242.

After a lapse of a predetermined period from the start of the spoutingof the rinse liquid, the controller 208 controls the spin motor 216 todecelerate the rotation of the substrate W stepwise from the sulfuricacid-containing liquid treatment speed to a puddling speed (e.g., about10 rpm). After the rotation speed of the substrate W is reduced to thepuddling speed (e.g., about 10 rpm), the controller 208 controls thespin motor 216 to maintain the rotation speed of the substrate W at thepuddling speed. Thus, a liquid film of the rinse liquid is retained in apuddle form on the entire upper surface of the substrate W.

After a lapse of a predetermined period from the time at which therotation speed of the substrate is reduced to the puddling speed (e.g.,about 10 rpm), the controller 208 closes the rinse liquid valve 232 tostop spouting the rinse liquid from the rinse liquid nozzle 230.

In turn, the controller 208 starts an organic solvent supplying step(second chemical liquid supplying step, Step T5). In this exemplaryprocess, the organic solvent supplying step (T5) is performed after therinsing step (T4) ends. That is, the rinse liquid intruding into theminute pattern on the front surface of the substrate W is replaced withthe organic solvent (IPA) having a lower surface tension prior to a spindrying step (T6) to be described later. This prevents the collapse ofthe pattern in the subsequent spin drying step (T6).

More specifically, the controller 208 controls the guard lift mechanismto move down the fifth to seventh guards 246 to 248 to the lowerposition (lowermost position), whereby the eighth guard 249 is broughtinto opposed relation to the peripheral surface of the substrate W asshown in FIG. 16. Further, the controller 208 controls the fourth armpivoting unit 236 to move the organic solvent nozzle 233 from the secondhome position 241 defined in the second outer space OS2 to the treatmentposition defined in the inner space IS.

At the second home position 241, the organic solvent nozzle 233 islocated above a pod (not shown). Before the start of the movement of theorganic solvent nozzle 233 from the second home position 241, a part ofIPA changed in quality with time after the last spouting is oftenpreliminarily dispensed from the organic solvent nozzle 233 at thesecond home position 241. For the preliminary dispensing, the controller208 opens the second suction valve 240 after stopping the spouting ofIPA from the organic solvent nozzle 233 at the second home position 241.Thus, IPA presenting in the portion of the organic solvent line 237downstream of the second branch position 237A is sucked. The suction ofIPA is continued until a front of IPA is retracted to a predeterminedstandby position in the organic solvent line 237. After the suction ofIPA, the controller 208 starts moving the organic solvent nozzle 233 tothe treatment position.

After the organic solvent nozzle 233 is located above the upper surfacecenter portion of the substrate W, the controller 208 opens the organicsolvent valve 238 with the rotation speed of the substrate W maintainedat the puddling speed. Thus, as shown in FIG. 16, IPA is spouted fromthe spout of the organic solvent nozzle 233 to be applied to the uppersurface center portion of the substrate W.

IPA is supplied to the upper surface of the substrate W, whereby therinse liquid on the upper surface of the substrate W is sequentiallyreplaced with IPA. Thus, a liquid film of IPA is retained in a puddleform on the upper surface of the substrate W as covering the entireupper surface of the substrate W. After the liquid film present on theentire upper surface of the substrate W is substantially replaced withthe IPA liquid film, the supply of IPA to the upper surface of thesubstrate W is continued. Therefore, IPA flows out from the periphery ofthe substrate W.

IPA flowing out from the periphery of the substrate W is received by theinner wall of the eighth guard 249 opposed to the peripheral surface ofthe substrate W. Then, IPA flows down on the inner wall of the eighthguard 249 and then drips from the lower edge of the eighth guard 249,and is received in the drain channel 245 to be guided from the bottom ofthe drain channel 245 to the drain unit (not shown) through the drainpipe (not shown).

After a lapse of a predetermined puddling period (e.g., about 10seconds) from the start of the spouting of IPA, the controller 208controls the spin motor 216 to accelerate the rotation of the substrateW from the puddling speed to a higher rotation speed (e.g., about 1000rpm) while continuously spouting IPA. After the rotation speed of thesubstrate W is increased to the higher rotation speed, the controller208 closes the organic solvent valve 238 to stop spouting IPA. After thespouting of IPA from the organic solvent nozzle 233 is stopped, thecontroller 208 opens the second suction valve 240. Thus, IPA is suckedfrom the portion of the organic solvent line 237 downstream of thesecond branch position 237A. The suction of IPA is continued until thefront of IPA is retracted to the predetermined standby position in theorganic solvent line 237.

After the suction of IPA, the controller 208 controls the fourth armpivoting unit 236 to move the organic solvent nozzle 233 from thetreatment position defined in the inner space IS to the second homeposition 241 defined in the second outer space OS2. Since the inside ofthe organic solvent line 237 is sucked prior to the start of themovement of the organic solvent nozzle 233, IPA is substantiallyprevented from dripping from the organic solvent nozzle 233 during themovement of the organic solvent nozzle 233 from the treatment position.When the organic solvent nozzle 233 is moved from the second homeposition 241 to the treatment position prior to the start of thetreatment, the sucking operation may also be performed in theaforementioned manner.

However, IPA has a relatively low viscosity. Therefore, there is apossibility that IPA drips from the organic solvent nozzle 233 when theorganic solvent nozzle 233 is moved from the second home position 241 orwhen the organic solvent nozzle 233 is moved back to the second homeposition 241. In this case, IPA dripping from the organic solvent nozzle233 is liable to be applied to the eighth guard 249 and the cover 255.The IPA applied to the eighth guard 249 flows on the outer wall of theeighth guard 249 and drips from the lower edge of the eighth guard 249to be received in the inner vat 260. The IPA applied to the cover 255flows into the lower outer space OSD through the gaps between the platesegments 256, the gaps between the tubular wall 250 and the platesegments 256 and the gaps between the side walls 215 and the platesegments 256 to be received in the second outer vat 262.

Further, the controller 208 performs the spin drying step (Step T6) withthe eighth guard 249 opposed to the peripheral surface of the substrateW. That is, the controller 208 maintains the rotation speed of thesubstrate W at the higher rotation speed (e.g., about 1000 rpm). Thus,IPA adhering to the substrate W is spun off to dry the substrate W.After the spin drying step (T6) is performed for a predetermined period,the controller 208 controls the spin motor 216 to stop the rotation ofthe spin chuck 203 (the rotation of the substrate W) (Step T7). Thus,the resist removing process is completed for the single substrate W.Then, the shutter 211 is opened, and the treated substrate W is unloadedfrom the treatment chamber 202 by the transport robot (not shown) (StepT8).

The SPM and IPA are an inappropriate combination of chemical liquidswhich are liable to cause a hazard when being accidentally brought intocontact with each other or mixed together. More specifically, theaccidental mixing of the SPM and IPA may cause explosion due to thedehydrating action of sulfuric acid contained in the SPM.

As described above, the SPM hardly drips from the sulfuricacid-containing liquid nozzle 221 during the movement of the sulfuricacid-containing liquid nozzle 221 from the first home position 229 tothe treatment position when the substrate treatment apparatus 201normally operates. When the substrate treatment apparatus 201 abnormallyoperates during the movement of the sulfuric acid-containing liquidnozzle 221, however, there is a possibility that the SPM drips from thesulfuric acid-containing liquid nozzle 221 located between the firsthome position 229 and the treatment position. The SPM dripping from thesulfuric acid-containing liquid nozzle 221 is received on the firstreception surface 263 of the first outer vat 261.

In the case of the organic solvent nozzle 233, on the other hand, thereis a possibility that IPA drips from the organic solve nozzle 233 duringthe movement between the second home position 241 and the treatmentposition even when the substrate treatment apparatus 201 normallyoperates. In addition, when the substrate treatment apparatus 201abnormally operates during the movement of the organic solvent nozzle233, there is a possibility that IPA drips from the organic solventnozzle 233 located between the second home position 241 and thetreatment position. The IPA dripping from the organic solvent nozzle 233is received on the second reception surface 265 of the second outer vat262.

In the second embodiment, as described above, the vat 209 provided onthe bottom of the treatment chamber 202 is divided into the inner vat260 provided on the bottom of the inner space IS, the first outer vat261 provided on the bottom of the first outer space OS1, and the secondouter vat 262 provided on the bottom of the second outer space OS2.During the movement of the sulfuric acid-containing liquid nozzle 221 inthe first outer space OS1, the SPM dripping from the sulfuricacid-containing liquid nozzle 221 is received on the first outer vat261. Further, IPA dripping from the organic solvent nozzle 233 duringthe movement between the second outer space OS2 and the position abovethe substrate W is received on the second outer vat 262 or the inner vat260. In other words, the vat 209 is divided into the first outer vat 261for the sulfuric acid-containing liquid nozzle 221 and the second outervat 262 for the organic solvent nozzle 233 according to the movementranges of the sulfuric acid-containing liquid nozzle 221 and the organicsolvent nozzle 233.

The first outer space OS1 and the second outer space OS2 are isolatedfrom each other in the bottom portion of the treatment chamber 202, sothat there is no liquid communication between the first outer vat 261and the second outer vat 262. Further, the first drain port 267 throughwhich the liquid received in the first outer vat 261 is drained and thesecond drain port 268 through which the liquid received in the secondouter vat 262 is drained are provided separately from each other.

As described above, the SPM and IPA are reliably prevented from beingaccidentally brought into contact with each other or mixed together inthe vat 209. Even if the chemical liquids liable to cause a hazard whenbeing accidentally brought into contact with each other or mixedtogether are used in combination, therefore, the substrate treatmentapparatus 201 is capable of reliably preventing the accidental mixing inthe vat.

FIG. 17 is a schematic diagram showing the upper portion of thetreatment chamber 202 according to a third embodiment of the presentinvention. FIG. 18 is a schematic diagram showing the bottom portion ofthe treatment chamber 202 shown in FIG. 17.

A substrate treatment apparatus 301 including the treatment chamber 202according to the third embodiment of the present invention is differentfrom the substrate treatment apparatus 201 according to the secondembodiment in that an alkaline chemical liquid supplying unit 290 isfurther provided which supplies SC1 (ammonia/hydrogen peroxide liquidmixture) as an exemplary alkaline chemical liquid (third chemicalliquid) to the substrate W held by the spin chuck 203. In the thirdembodiment, three types of chemical liquids are usable.

In the third embodiment, another partition wall 302 is provided inaddition to the two partition walls 257 between the tubular wall 250 andthe side walls 215. That is, the third embodiment differs from thesecond embodiment in that a total of three partition walls are provided.

In FIGS. 17 and 18, components corresponding to those of the secondembodiment will be designated by the same reference characters as inFIGS. 8 to 16, and duplicate description will be omitted.

The alkaline chemical liquid supplying unit 290 includes an alkalinechemical liquid nozzle 291 which spouts SC1 toward the front surface ofthe substrate W, a fifth nozzle arm 292 having a distal end to which thealkaline chemical liquid nozzle 291 is attached, a fifth pivot shaft 293extending vertically on a lateral side of the spin chuck 203 andpivotally supporting the fifth nozzle arm 292, and a fifth arm pivotingunit (not shown) which rotates the fifth pivot shaft 293 to move thefifth nozzle arm 292 to thereby move the alkaline chemical liquid nozzle291. The alkaline chemical liquid nozzle 291 is, for example, a straightnozzle which spouts SC1 in the form of continuous stream, and isattached to the horizontally extending fifth nozzle arm 292, forexample, with its spout directed downward. The fifth nozzle arm 292extends horizontally.

The fifth arm pivoting unit pivots the fifth nozzle arm 292 about thefifth pivot shaft 293 to move the alkaline chemical liquid nozzle 291horizontally along an arcuate path. The fifth arm pivoting unithorizontally moves the alkaline chemical liquid nozzle 291 between atreatment position such that SCI spouted from the alkaline chemicalliquid nozzle 291 is applied to the upper surface of the substrate W anda fifth {third} home position 294 defined adjacent the spin chuck 203 asseen in plan. Further, the fifth arm pivoting unit horizontally movesthe alkaline chemical liquid nozzle 291 between a center position suchthat SC1 spouted from the alkaline chemical liquid nozzle 291 is appliedto the upper surface center portion of the substrate W and a peripheralposition such that SC1 spouted from the alkaline chemical liquid nozzle291 is applied to the upper surface peripheral portion of the substrateW. The center position and the peripheral position are each defined asthe treatment position. The third home position 294 is defined in thefirst outer space OS1. The fifth pivot shaft 293 is also disposed in thefirst outer space OS1.

The partition wall 302 is postured vertically, and extends radially fromthe tubular wall 250. The partition wall 302 circumferentiallypartitions the outer space OS1 (see FIG. 9) of the second embodimentinto a third outer space OS3 and a fourth outer space OS4 as seen inplan. The partition wall 302 separates the third and fourth outer spacesOS3, OS4 from each other, so that the first communication hole 253 isopposed to the third outer space OS3. An upper edge of the partitionwall 302 horizontally extends at a height level slightly lower than theupper edge of the tubular wall 250. The third outer space OS3 and thefourth outer space OS4 are isolated from each other in a lower portion(including the bottom portion) of the treatment chamber 202 by thepartition wall 302. Further, the third and fourth outer spaces OS3, OS4are each isolated from the second outer space OS2.

The first outer vat 261 (see FIG. 10 and the like) of the secondembodiment is also divided into two parts, i.e., a third outer vat 303and a fourth outer vat 304, as the first outer space OS1 is divided intothe third outer space OS3 and the fourth outer space OS4. That is, thevat 209 includes the inner vat 260, the second outer vat 262, the thirdouter vat 303 disposed on the bottom of the third outer space OS3, andthe fourth outer vat 304 disposed on the bottom of the fourth outerspace OS4.

The third outer vat 303 is a vat for receiving the SPM (first vat),while the fourth outer vat 304 is a vat (third vat) for receiving SC1.The third outer vat 303 is dimensioned and configured in conformity withthe bottom of the third outer space OS3, and covers the entire bottom ofthe third outer space OS3 from below. The entire periphery of the thirdouter vat 303 is welded to be connected to the lower edges of thepartition walls 257, 302 and the tubular wall 250 for prevention ofliquid leakage from the third outer space OS3.

The fourth outer vat 304 is dimensioned and configured in conformitywith the bottom of the fourth outer space OS4, and covers the entirebottom of the fourth outer space OS4 from below. The entire periphery ofthe fourth outer vat 304 is welded to be connected to the lower edges ofthe partition walls 257, 302 and the tubular wall 250 for prevention ofliquid leakage from the fourth outer space OS4.

The first outer vat 261 is divided into two parts, i.e., the third andfourth outer vats 303, 304. The third outer vat 303 has a thirdreception surface 305, while the fourth outer vat 304 has a fourthreception surface 306. Therefore, the first reception surface 263 (seeFIG. 10) is also divided into two parts, i.e., the third receptionsurface 305 and the fourth reception surface 306. The lowermost portion264 of the first reception surface 263 (also see FIG. 10) is provided onthe third reception surface 305, and a portion of the third receptionsurface 305 excluding the first lowermost portion 264 is inclineddownward toward the first lowermost portion 264 with respect to thehorizontal directions X. Therefore, the SPM received on differentportions of the third reception surface 305 flows toward the firstlowermost portion 264 due to height differences from the first lowermostportion 264.

The fourth reception surface 306 has a fourth lowermost portion 307located adjacent the first lowermost portion 264 on a side of thepartition wall 302 opposite from the first lowermost portion 264. Aportion of the fourth reception surface 306 excluding the fourthlowermost portion 307 is inclined downward toward the fourth lowermostportion 307 with respect to the horizontal directions X. Therefore, SC1received on different portions of the fourth reception surface 306 flowstoward the fourth lowermost portion 307 due to height differences fromthe fourth lowermost portion 307.

A third drain port 308 is provided adjacent the first drain port 267 inan outer peripheral portion of the inner reception surface 271 of theinner vat 260. A third drain pipe (not shown) is connected to the thirddrain port 308. A downstream end portion of the third drain pipe extendsto a third drain unit (not shown) different from the first and seconddrain units.

The tubular wall 250 has a third communication hole 309 provided in alower edge portion thereof as extending therethrough to be opposed tothe fourth lowermost portion 307 of the fourth reception surface 306.

As shown in FIG. 18, the third drain port 308 is connected to the fourthlowermost portion 307 of the fourth reception surface 306 through asecond tube 310. SC1 flowing on the fourth reception surface 306 toreach the fourth lowermost portion 307 is guided to the third drain port308 through the second tube 310. That is, the second tube 310 isprovided as a bypass for connection between the fourth lowermost portion307 and the third drain port 308, so that SC1 received on the fourthreception surface 306 can be guided to the third drain port 308 whilebeing prevented from flowing on the inner reception surface 271 of theinner vat 260. A chemical-resistant material such as a fluororesin isused as a material for the second tube 310.

A proximal end of the second tube 310 is connected to the fourthlowermost portion 307 (a portion of the tubular wall 250 opposed to thefourth lowermost portion 307) via a first pipe joint 330 similar to thefirst pipe joint 320. The first pipe joint 330 has a joint body 331which closes the third communication hole 309 of the tubular wall 250 tobe fixed to the tubular wall 250. The joint body 331 has an inlet port311, which is opposed to the fourth lowermost portion 307. A distal endof the second tube 310 is connected to the third drain port 308 via apipe joint 312 similar to the pipe joint 275 (see FIG. 13).

SC1 received on different portions of the fourth reception surface 306of the fourth outer vat 304 flows toward the fourth lowermost portion307 due to height differences on the fourth reception surface 306. SC1reaching the fourth lowermost portion 307 flows into the second tube 310via the inlet port 311 opening in the third communication hole 309 tomove into the third drain pipe due to a height difference from thesecond tube 310. SC1 flowing into the third drain pipe is sent to thethird drain unit (not shown) to be drained.

According to the third embodiment, as described above, not only IPA butalso SC1 is reliably prevented from being accidentally brought intocontact with or mixed with the SPM. This reliably prevents theaccidental mixing of the alkali and the acid in the vat.

While the three embodiments of the present invention have thus beendescribed, the invention may be embodied in other ways.

In the exemplary process according to the first embodiment, the firstcleaning liquid supplying step is performed in the rinsing step (S4)byway of example. However, the first cleaning liquid supplying step maybe started after the end of the rinsing step (S4) and the organicsolvent supplying step (S5) may be started after the end of the firstcleaning liquid supplying step. Further, the first cleaning liquidsupplying step may be started before the end of the rinsing step (S4),and the organic solvent supplying step (S5) may be started after the endof the first cleaning liquid supplying step after the rinsing step (S4).

In the exemplary process according to the first embodiment, the secondcleaning liquid supplying step is performed in the organic solventsupplying step (S5) byway of example, but the second cleaning liquidsupplying step may be performed before the start of the spin drying step(S6) after the end of the organic solvent supplying step (S5). Further,the second cleaning liquid supplying step may be started before the endof the organic solvent supplying step (S5), and the spin drying step(S6) may be started after the end of the second cleaning liquidsupplying step after the organic solvent supplying step (S5).

In the exemplary process according to the first embodiment, both thesecond and third cleaning liquid supplying steps are performed forremoving IPA adhering to (or remaining on) the first cup 42 and the likeby way of example, but it is sufficient to perform at least one of thesecond and third cleaning liquid supplying steps. There is no need toperform both of the second and third cleaning liquid supplying steps.

In the exemplary process according to the first embodiment, the frontsurface of the substrate W is treated with IPA retained in the puddleform on the substrate W in the organic solvent supplying step (S5) byway of example not by way of limitation. In the organic solventsupplying step (S5), the substrate W may be rotated at a relatively highrotation speed (e.g., several hundreds rpm).

In the first cleaning liquid supplying step according to the firstembodiment, a threshold may be provided for the rotation speed of thesubstrate W in the rinsing step (S4), and the timing of the end of thefirst cleaning liquid supplying step may be determined according to thethreshold.

If the substrate W is rotated at a rotation speed not higher than thethreshold when the first cleaning liquid supplying step ends in therinsing step (S4) according to the first embodiment, the cleaning of theinner wall of the first cup 42 and the like may be regarded as beingincomplete, and the opening of the organic solvent valve 38 may beprohibited in the organic solvent supplying step (S5) to be subsequentlyperformed (interlock).

The timings of the end of the first to third cleaning liquid supplyingsteps may be determined based on cumulative flow amounts (cumulative useamounts) of the cleaning liquid in the first to third cleaning liquidsupplying steps. More specifically, cumulative flow meters may berespectively provided for the cleaning liquid supplying units 77, 79,and the cumulative flow amounts may be calculated based on the values ofthe cumulative flow meters.

If the cumulative flow amount of the cleaning liquid is not higher thanthe threshold when the first to third cleaning liquid supplying stepseach end in the first embodiment, the cleaning of the inner wall of thefirst cup 42 and the like may be regarded as being incomplete, and theopening of the sulfuric acid-containing liquid valve 32 may beprohibited in the organic solvent supplying step (S5) or the sulfuricacid-containing liquid supplying step (S3) to be subsequently performed(interlock).

In the first to third cleaning liquid supplying steps of the firstembodiment, the timings of the end of the first to third cleaning liquidsupplying steps may be determined based on the cumulative flow amounts(cumulative use amounts) of the cleaning liquid in the respectivecleaning liquid supplying steps. More specifically, cumulative flowmeters may be respectively provided for the cleaning liquid supplyingunits 77, 79, and the cumulative flow amounts may be calculated based onthe values of the cumulative flow amounts.

If the cumulative flow amount of the cleaning liquid is not higher thanthe threshold when the first to third cleaning liquid supplying stepseach end, the cleaning of the inner wall of the first cup 42 and thelike may be regarded as being incomplete, and the opening of the organicsolvent valve 38 may be prohibited in the organic solvent supplying step(S5) or the sulfuric acid-containing liquid supplying step (S3) to besubsequently performed (interlock).

In the first embodiment, the first cup 42 out of the plurality of cups(the first cup 42, the second cup 43 and cup portion 63) is cleaned byway of example, but the second cup 43 or the cup portion 63 may becleaned.

Where the second guard 45 is opposed to the peripheral surface of thesubstrate W in the sulfuric acid-containing liquid supplying step (S3),for example, the second cup 43 may be cleaned in the first cleaningliquid supplying step. In this case, the controller 8 controls the guardlift unit 48 to bring the second guard 45 into opposed relation to theperipheral surface of the substrate W, and controls the second recoveryvalve 100A and the second drain valve 101A to set the destination of thesecond common pipe 98 to the second recovery pipe 100 in the sulfuricacid-containing liquid supplying step (S3). In the first cleaning liquidsupplying step, the controller 8 controls the guard lift unit 48 tobring the second guard 45 into opposed relation to the peripheralsurface of the substrate W, and controls the second recovery valve 100Aand the second drain valve 101A to switch the destination of the secondcommon pipe 98 to the second drain pipe 101. Further, the controller 8opens the first cleaning liquid valve 84 to spout the cleaning liquidfrom the first cleaning liquid nozzles 76. Thus, the cleaning liquidspouted from the first cleaning liquid nozzles 76 is sprayed onto theperipheral surface and the bottom surface of the outer periphery 15A,whereby the SPM adhering to the peripheral surface and the bottomsurface of the outer periphery 15A is washed away. Further, the cleaningliquid spouted from the first cleaning liquid nozzles 76 is splashed onthe peripheral surface and the bottom surface of the outer periphery 15Ato be applied to the inner wall of the guide portion 62 of the secondguard 45, and flows down on the inner wall of the cylindrical portion 64(see FIG. 2 and the like) and drips from the lower edge of thecylindrical portion 64 to be received in the second drain/recoverychannel 55 (see FIG. 2 and the like) of the second cup 43. The cleaningliquid supplied to the second drain/recovery channel 55 movescircumferentially of the second cup 43 toward the second drain/recoveryport 97 in the second drain/recovery channel 55 to be guided to thesecond common pipe 98 from the second drain/recovery port 97. Since thedestination of the second common pipe 98 is set to the second drainpipe101, the cleaning liquid guided to the second common pipe 87 is furtherguided to the drain unit (not shown) through the second drain pipe 101to be drained. The cleaning liquid flows through the second cup 43 andthe second common pipe 98, whereby the inner wall of the second cup 43and the pipe wall of the second common pipe 98 are cleaned.

Where the third guard 46 is opposed to the peripheral surface of thesubstrate W in the sulfuric acid-containing liquid supplying step (S3),the cup portion 63 may be cleaned in the first cleaning liquid supplyingstep. In this case, the controller 8 controls the guard lift unit 48 tobring the third guard 46 into opposed relation to the peripheral surfaceof the substrate W, and controls the third recovery valve 105A and thethird drain valve 106A to set the destination of the third common pipe103 to the third recovery pipe 105 in the sulfuric acid-containingliquid supplying step (S3). In the first cleaning liquid supplying step,the controller 8 controls the guard lift unit 48 to bring the thirdguard 46 into opposed relation to the peripheral surface of thesubstrate W, and controls the third recovery valve 105A and the thirddrain valve 106A to switch the destination of the third common pipe 103to the third drain pip 106. Further, the controller 8 opens the firstcleaning liquid valve 84 to spout the cleaning liquid from the firstcleaning liquid nozzles 76. Thus, the cleaning liquid spouted from thefirst cleaning liquid nozzles 76 is sprayed onto the peripheral surfaceand the bottom surface of the outer periphery 15A, whereby the SPMadhering to the peripheral surface and the bottom surface of the outerperiphery 15A is washed away. Further, the cleaning liquid spouted fromthe first cleaning liquid nozzles 76 is splashed on the peripheralsurface and the bottom surface of the outer periphery 15A to be appliedto the inner wall of the lower portion 68 of the third guard 45 (seeFIG. 2 and the like), and flows down on the inner wall and drips fromthe lower edge of the lower portion 68 to be received in the thirddrain/recovery channel 66 of the cup portion 63 of the second guard 45(see FIG. 2 and the like). The cleaning liquid supplied to the thirddrain/recovery channel 66 moves circumferentially of the cup portion 63toward the third drain/recovery port 102 in the third drain/recoverychannel 66 to be guided to the third common pipe 103 from the thirddrain/recovery port 102. Since the destination of the third common pipe103 is set to the third drain pipe 106, the cleaning liquid guided tothe third common pipe 103 is further guided to the drain unit (notshown) through the third drain pipe 106 to be drained. The cleaningliquid flows through the cup portion 63 and the third common pipe 103,whereby the inner wall of the cup portion 63 and the pipe wall of thethird common pipe 103 are cleaned.

In the first embodiment, the common pipes 93, 98, 103 are respectivelyconnected to the bottoms of the cups 42, 43, 63, and the destinations ofthe liquids (treatment liquid or cleaning liquid) flowing through thecommon pipes 93, 98, 103 are each switched between the recovery pipe 95,100, 105 and the drain pipe 96, 101, 106 byway of example. Without thisarrangement, the drain pipes 96, 101, 106 may be respectively connectedto the bottoms of the cups 42, 43, 63. That is, drain ports may beprovided instead of the drain/recovery ports 92, 97, 102, and the drainpipes 96, 101, 106 may be respectively connected to the drain/recoveryports 92, 97, 102.

In the first embodiment, a three-way valve may be used for switching thedestination of the liquid flowing through the common pipe 93, 98, 103between the recovery pipe 95, 100, 105 and the drain pipe 96, 101, 106.

In the first embodiment, the cleaning liquid spouted from the firstcleaning liquid nozzles 76 is sprayed onto both the peripheral surfaceand the bottom surface of the outer periphery 15A by way of example, butthe cleaning liquid may be sprayed onto at least one of the peripheralsurface and the bottom surface of the outer periphery 15A.

In the first embodiment, the cleaning liquid spouted from the secondcleaning liquid nozzles 78 is once applied to the lower portion 58 andthen supplied to the inner wall of the first cup 42 by way of example,but the cleaning liquid spouted from the second cleaning liquid nozzles78 may be supplied directly to the inner wall of the first cup 42 (e.g.,the inner wall of the bottom 51).

In the first embodiment, the second cleaning liquid outlet ports 81 ofthe second cleaning liquid nozzles 78 are directed obliquely downward byway of example, but the second cleaning liquid outlet ports 81 may bedirected horizontally.

In the first embodiment, the treatment cup 7 includes the plurality ofcups by way of example, but the present invention may be applied to atreatment cup including a single cup.

In the first embodiment, the first and second cleaning liquid nozzles76, 78 are configured such that the first and second cleaning liquidoutlet ports 80, 81 are provided in the taper surface 24A (outerperipheral surface of the boss 21), but may each have a nozzle casingprovided separately from the boss 21.

In the first embodiment, the first cleaning nozzles 76 and the secondcleaning nozzles 78 are used in the respective cleaning liquid supplyingsteps by way of example, but the first cleaning nozzles 76 or the secondcleaning nozzles 78 may be used.

In the second embodiment, the vat (second vat) for receiving IPAincludes the inner vat 260 and the second outer vat 262 byway ofexample, but may include only the second outer vat 262. In this case,the inner space IS and the second outer space OS2 may be isolated fromeach other in the lower portion (including the bottom portion) of thetreatment chamber 202.

The sulfuric acid-containing liquid nozzle 221, the organic solventnozzle 233 and the alkaline chemical liquid nozzle 291 are eachhorizontally moved along the arcuate path between the treatment positionand the home position 229, 241, 294 by way of example, but may be slidlinearly.

In the second embodiment, the sulfuric acid-containing liquid line 225and the organic solvent line 237 are respectively branched into thefirst suction line 227 and the second suction line 239. Suctionmechanisms may be respectively provided in the sulfuric acid-containingliquid valve 226 which opens and closes the sulfuric acid-containingliquid line 225 and in the organic solvent valve 238 which opens andcloses the organic solvent line 237, and the SPM and IPA may berespectively sucked from the sulfuric acid-containing liquid line 225and the organic solvent line 237 by driving the suction mechanisms.

Further, the arrangement for sucking the sulfuric acid-containing liquidline 225 or the organic solvent line 237 (the first suction line 227,the first suction valve 228 and the like or the second suction line 239,the second suction valve 240 and the like) may be obviated.

In the embodiments described above, the SPM is used as the sulfuricacid-containing liquid by way of example, but sulfuric acid may be usedas the sulfuric acid-containing liquid.

In the embodiments described above, the organic solvent includes atleast one of IPA, methanol, ethanol, HFE (hydrofluoroether) and acetone.These organic solvents may be used either alone or in combination. Forexample, a liquid mixture of IPA and acetone or a liquid mixture of IPAand methanol may be used as the organic solvent.

In the embodiments described above, the sulfuric acid-containing liquidsuch as the SPM and the organic solvent such as IPA are used incombination as the first chemical liquid and the second chemical liquidwhich are liable to cause a hazard when being accidentally brought intocontact with each other or mixed together by way of example. Otherexemplary combinations of chemical liquids which are liable to cause ahazard by the accidental mixing include a combination of a nitricacid-containing liquid such as nitric acid and nitrohydrofluoric acid (aliquid mixture of hydrofluoric acid and nitric acid) and an organicsolvent, and a combination of nitrohydrochloric acid and sulfuric acid.

The present invention may be applied not only to the combination of thefirst chemical liquid and the second chemical liquid which are liable tocause a hazard when being accidentally brought into contact with eachother or mixed together but also to a combination of a first chemicalliquid and a second chemical liquid which are inappropriate for themixing. For example, the present invention is applicable to acombination of an acid and an alkali which produce a reaction productwhen being accidentally brought into contact with each other or mixedtogether.

While the present invention has been described in detail by way of theembodiments thereof, it should be understood that these embodiments aremerely illustrative of the technical principles of the present inventionbut not limitative of the invention. The spirit and scope of the presentinvention are to be limited only by the appended claims.

This application corresponds to Japanese Patent Application Nos.2014-165555 and 2014-165556 filed in the Japan Patent Office on Aug. 15,2014, the disclosure of which is incorporated herein by reference intheir entireties.

What is claimed is:
 1. A substrate treatment apparatus comprising: atreatment chamber; a substrate holding mechanism provided in thetreatment chamber for holding a substrate; a tubular treatment cupprovided in the treatment chamber and surrounding the substrate holdingmechanism; a first chemical liquid nozzle which spouts a first chemicalliquid to the substrate held by the substrate holding mechanism; asecond chemical liquid nozzle which spouts a second chemical liquiddifferent from the first chemical liquid to the substrate held by thesubstrate holding mechanism; a first moving mechanism which moves thefirst chemical liquid nozzle between a first outer space and an upperposition above the substrate held by the substrate holding mechanism,the first outer space being a predetermined space defined outside thetreatment cup in the treatment chamber as seen in plan; a second movingmechanism which moves the second chemical liquid nozzle between a secondouter space different from the first outer space and the upper positionabove the substrate held by the substrate holding mechanism, the secondouter space being a predetermined space defined outside the treatmentcup in the treatment chamber as seen in plan; a first vat disposed atleast in a bottom of the first outer space for receiving liquid fromabove and guiding the liquid toward a first drain port; and a second vatdisposed in a bottom of the second outer space for receiving liquid fromabove and guiding the received liquid toward a second drain portdifferent from the first drain port; wherein at least bottom portions ofthe first outer space and the second outer space are isolated from eachother.
 2. The substrate treatment apparatus according to claim 1,wherein the first moving mechanism includes a mechanism of moving thefirst chemical liquid nozzle between a first home position defined inthe first outer space and a treatment position defined above thesubstrate held by the substrate holding mechanism, wherein the secondmoving mechanism includes a mechanism of moving the second chemicalliquid nozzle between a second home position defined in the second outerspace and a treatment position defined above the substrate held by thesubstrate holding mechanism.
 3. The substrate treatment apparatusaccording to claim 1, wherein the second vat extends over the bottom ofthe second outer space and the bottom of an inner space, the inner spacebeing a predetermined space defined inside the treatment cup as seen inplan.
 4. The substrate treatment apparatus according to claim 1, whereinthe upper surface of the first bat is inclined so that the liquidreceived by the upper surface of the first bat flows toward the firstdrain port due to a difference in elevation of the upper surface of thefirst bat, wherein the upper surface of the second bat is inclined sothat the liquid received by the upper surface of the second bat flowstoward the second drain port due to a difference in elevation of theupper surface of the second bat.
 5. The substrate treatment apparatusaccording to claim 1, wherein the first moving mechanism includes afirst pivoting mechanism of pivoting the first chemical liquid nozzlearound a first pivoting axis; and wherein the second moving mechanismincludes a second pivoting mechanism of pivoting the second chemicalliquid nozzle around a second pivoting axis.
 6. The substrate treatmentapparatus according to claim 1, further comprising: a first chemicalliquid supply line of supplying the first chemical liquid to the firstchemical liquid nozzle; and a suction mechanism for sucking the insideof the first chemical liquid supply line.
 7. The substrate treatmentapparatus according to claim 1, wherein the first chemical liquidincludes a sulfuric acid-containing liquid, wherein the second chemicalliquid includes an organic solvent.
 8. The substrate treatment apparatusaccording to claim 1, further comprising: a controller of controllingthe first moving mechanism, wherein the controller controls perform astep of moving the first chemical liquid nozzle between a region locatedabove the first bat in the first outer space and the upper positionabove the substrate held by the substrate holding mechanism.
 9. Thesubstrate treatment apparatus according to claim 1, further comprising:a controller of controlling the second moving mechanism, wherein thecontroller controls perform a step of moving the second chemical liquidnozzle between a region located above the second bat in the second outerspace and the upper position above the substrate held by the substrateholding mechanism.